diff --git a/config/check_spidermonkey_style.py b/config/check_spidermonkey_style.py
index c7e8d2934c6f..accccdbdc560 100644
--- a/config/check_spidermonkey_style.py
+++ b/config/check_spidermonkey_style.py
@@ -302,6 +302,28 @@ def module_name(name):
     return name.replace('inlines.h', '').replace('-inl.h', '').replace('.h', '').replace('.cpp', '')
 
 
+def is_module_header(enclosing_inclname, header_inclname):
+    '''Determine if an included name is the "module header", i.e. should be
+    first in the file.'''
+
+    module = module_name(enclosing_inclname)
+
+    # Normal case, e.g. module == "foo/Bar", header_inclname == "foo/Bar.h".
+    if module == module_name(header_inclname):
+        return True
+
+    # A public header, e.g. module == "foo/Bar", header_inclname == "js/Bar.h".
+    m = re.match(r'js\/(.*)\.h', header_inclname)
+    if m is not None and module.endswith('/' + m.group(1)):
+        return True
+
+    # A weird public header case.
+    if module == 'jsmemorymetrics' and header_inclname == 'js/MemoryMetrics.h':
+        return True
+
+    return False
+
+
 class Include(object):
     '''Important information for a single #include statement.'''
 
@@ -313,7 +335,7 @@ class Include(object):
     def isLeaf(self):
         return True
 
-    def section(self, module):
+    def section(self, enclosing_inclname):
         '''Identify which section inclname belongs to.
 
         The section numbers are as follows.
@@ -333,12 +355,9 @@ class Include(object):
         if not self.inclname.endswith('.h'):
             return 7
 
-        # A couple of modules have the .h file in js/ and the .cpp file elsewhere and so need special
-        # handling.
-        if module == module_name(self.inclname) or \
-           module == 'jsmemorymetrics' and self.inclname == 'js/MemoryMetrics.h' or \
-           module == 'vm/PropertyKey' and self.inclname == 'js/PropertyKey.h' or \
-           module == 'vm/StructuredClone' and self.inclname == 'js/StructuredClone.h':
+        # A couple of modules have the .h file in js/ and the .cpp file elsewhere and so need
+        # special handling.
+        if is_module_header(enclosing_inclname, self.inclname):
             return 0
 
         if '/' in self.inclname:
@@ -452,8 +471,6 @@ def do_file(filename, inclname, file_kind, f, all_inclnames, included_h_inclname
                 if inclname == include.inclname:
                     error(filename, include.linenum, 'the file includes itself')
 
-    module = module_name(inclname)
-
     def check_includes_order(include1, include2):
         '''Check the ordering of two #include statements.'''
 
@@ -461,8 +478,8 @@ def do_file(filename, inclname, file_kind, f, all_inclnames, included_h_inclname
            include2.inclname in oddly_ordered_inclnames:
             return
 
-        section1 = include1.section(module)
-        section2 = include2.section(module)
+        section1 = include1.section(inclname)
+        section2 = include2.section(inclname)
         if (section1 > section2) or \
            ((section1 == section2) and (include1.inclname.lower() > include2.inclname.lower())):
             error(filename, str(include1.linenum) + ':' + str(include2.linenum),
diff --git a/js/ipc/JavaScriptParent.h b/js/ipc/JavaScriptParent.h
index 041149e3dde8..afd18b6652e5 100644
--- a/js/ipc/JavaScriptParent.h
+++ b/js/ipc/JavaScriptParent.h
@@ -10,6 +10,7 @@
 
 #include "JavaScriptShared.h"
 #include "mozilla/jsipc/PJavaScriptParent.h"
+#include "jsclass.h"
 
 #ifdef XP_WIN
 #undef GetClassName
diff --git a/js/public/ProfilingStack.h b/js/public/ProfilingStack.h
new file mode 100644
index 000000000000..36af5969034d
--- /dev/null
+++ b/js/public/ProfilingStack.h
@@ -0,0 +1,94 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef js_ProfilingStack_h
+#define js_ProfilingStack_h
+
+#include "jsbytecode.h"
+#include "jstypes.h"
+
+#include "js/Utility.h"
+
+struct JSRuntime;
+class JSScript;
+
+namespace js {
+
+// A call stack can be specified to the JS engine such that all JS entry/exits
+// to functions push/pop an entry to/from the specified stack.
+//
+// For more detailed information, see vm/SPSProfiler.h.
+//
+class ProfileEntry
+{
+    // All fields are marked volatile to prevent the compiler from re-ordering
+    // instructions. Namely this sequence:
+    //
+    //    entry[size] = ...;
+    //    size++;
+    //
+    // If the size modification were somehow reordered before the stores, then
+    // if a sample were taken it would be examining bogus information.
+    //
+    // A ProfileEntry represents both a C++ profile entry and a JS one. Both use
+    // the string as a description, but JS uses the sp as NULL to indicate that
+    // it is a JS entry. The script_ is then only ever examined for a JS entry,
+    // and the idx is used by both, but with different meanings.
+    //
+    const char * volatile string; // Descriptive string of this entry
+    void * volatile sp;           // Relevant stack pointer for the entry
+    JSScript * volatile script_;  // if js(), non-null script which is running
+    int32_t volatile idx;         // if js(), idx of pc, otherwise line number
+
+  public:
+    // All of these methods are marked with the 'volatile' keyword because SPS's
+    // representation of the stack is stored such that all ProfileEntry
+    // instances are volatile. These methods would not be available unless they
+    // were marked as volatile as well.
+
+    bool js() volatile {
+        JS_ASSERT_IF(sp == NULL, script_ != NULL);
+        return sp == NULL;
+    }
+
+    uint32_t line() volatile { JS_ASSERT(!js()); return idx; }
+    JSScript *script() volatile { JS_ASSERT(js()); return script_; }
+    void *stackAddress() volatile { return sp; }
+    const char *label() volatile { return string; }
+
+    void setLine(uint32_t aLine) volatile { JS_ASSERT(!js()); idx = aLine; }
+    void setLabel(const char *aString) volatile { string = aString; }
+    void setStackAddress(void *aSp) volatile { sp = aSp; }
+    void setScript(JSScript *aScript) volatile { script_ = aScript; }
+
+    // We can't know the layout of JSScript, so look in vm/SPSProfiler.cpp.
+    JS_FRIEND_API(jsbytecode *) pc() volatile;
+    JS_FRIEND_API(void) setPC(jsbytecode *pc) volatile;
+
+    static size_t offsetOfString() { return offsetof(ProfileEntry, string); }
+    static size_t offsetOfStackAddress() { return offsetof(ProfileEntry, sp); }
+    static size_t offsetOfPCIdx() { return offsetof(ProfileEntry, idx); }
+    static size_t offsetOfScript() { return offsetof(ProfileEntry, script_); }
+
+    // The index used in the entry can either be a line number or the offset of
+    // a pc into a script's code. To signify a NULL pc, use a -1 index. This is
+    // checked against in pc() and setPC() to set/get the right pc.
+    static const int32_t NullPCIndex = -1;
+};
+
+JS_FRIEND_API(void)
+SetRuntimeProfilingStack(JSRuntime *rt, ProfileEntry *stack, uint32_t *size,
+                         uint32_t max);
+
+JS_FRIEND_API(void)
+EnableRuntimeProfilingStack(JSRuntime *rt, bool enabled);
+
+JS_FRIEND_API(jsbytecode*)
+ProfilingGetPC(JSRuntime *rt, JSScript *script, void *ip);
+
+} // namespace js
+
+#endif  /* js_ProfilingStack_h */
diff --git a/js/public/Value.h b/js/public/Value.h
index 394c25e09e8c..57ec128e9b29 100644
--- a/js/public/Value.h
+++ b/js/public/Value.h
@@ -1907,6 +1907,13 @@ extern JS_PUBLIC_DATA(const jsval) JSVAL_FALSE;
 extern JS_PUBLIC_DATA(const jsval) JSVAL_TRUE;
 extern JS_PUBLIC_DATA(const jsval) JSVAL_VOID;
 
+namespace JS {
+
+extern JS_PUBLIC_DATA(const Handle<Value>) NullHandleValue;
+extern JS_PUBLIC_DATA(const Handle<Value>) UndefinedHandleValue;
+
+}
+
 #undef JS_VALUE_IS_CONSTEXPR
 #undef JS_RETURN_LAYOUT_FROM_BITS
 
diff --git a/js/src/config/check_spidermonkey_style.py b/js/src/config/check_spidermonkey_style.py
index c7e8d2934c6f..accccdbdc560 100644
--- a/js/src/config/check_spidermonkey_style.py
+++ b/js/src/config/check_spidermonkey_style.py
@@ -302,6 +302,28 @@ def module_name(name):
     return name.replace('inlines.h', '').replace('-inl.h', '').replace('.h', '').replace('.cpp', '')
 
 
+def is_module_header(enclosing_inclname, header_inclname):
+    '''Determine if an included name is the "module header", i.e. should be
+    first in the file.'''
+
+    module = module_name(enclosing_inclname)
+
+    # Normal case, e.g. module == "foo/Bar", header_inclname == "foo/Bar.h".
+    if module == module_name(header_inclname):
+        return True
+
+    # A public header, e.g. module == "foo/Bar", header_inclname == "js/Bar.h".
+    m = re.match(r'js\/(.*)\.h', header_inclname)
+    if m is not None and module.endswith('/' + m.group(1)):
+        return True
+
+    # A weird public header case.
+    if module == 'jsmemorymetrics' and header_inclname == 'js/MemoryMetrics.h':
+        return True
+
+    return False
+
+
 class Include(object):
     '''Important information for a single #include statement.'''
 
@@ -313,7 +335,7 @@ class Include(object):
     def isLeaf(self):
         return True
 
-    def section(self, module):
+    def section(self, enclosing_inclname):
         '''Identify which section inclname belongs to.
 
         The section numbers are as follows.
@@ -333,12 +355,9 @@ class Include(object):
         if not self.inclname.endswith('.h'):
             return 7
 
-        # A couple of modules have the .h file in js/ and the .cpp file elsewhere and so need special
-        # handling.
-        if module == module_name(self.inclname) or \
-           module == 'jsmemorymetrics' and self.inclname == 'js/MemoryMetrics.h' or \
-           module == 'vm/PropertyKey' and self.inclname == 'js/PropertyKey.h' or \
-           module == 'vm/StructuredClone' and self.inclname == 'js/StructuredClone.h':
+        # A couple of modules have the .h file in js/ and the .cpp file elsewhere and so need
+        # special handling.
+        if is_module_header(enclosing_inclname, self.inclname):
             return 0
 
         if '/' in self.inclname:
@@ -452,8 +471,6 @@ def do_file(filename, inclname, file_kind, f, all_inclnames, included_h_inclname
                 if inclname == include.inclname:
                     error(filename, include.linenum, 'the file includes itself')
 
-    module = module_name(inclname)
-
     def check_includes_order(include1, include2):
         '''Check the ordering of two #include statements.'''
 
@@ -461,8 +478,8 @@ def do_file(filename, inclname, file_kind, f, all_inclnames, included_h_inclname
            include2.inclname in oddly_ordered_inclnames:
             return
 
-        section1 = include1.section(module)
-        section2 = include2.section(module)
+        section1 = include1.section(inclname)
+        section2 = include2.section(inclname)
         if (section1 > section2) or \
            ((section1 == section2) and (include1.inclname.lower() > include2.inclname.lower())):
             error(filename, str(include1.linenum) + ':' + str(include2.linenum),
diff --git a/js/src/jsapi.cpp b/js/src/jsapi.cpp
index 96c97e6de95f..b556031fb4cf 100644
--- a/js/src/jsapi.cpp
+++ b/js/src/jsapi.cpp
@@ -128,15 +128,6 @@ const jsid JSID_VOID  = { size_t(JSID_TYPE_VOID) };
 const jsid JSID_EMPTY = { size_t(JSID_TYPE_OBJECT) };
 #endif
 
-const jsval JSVAL_NULL  = IMPL_TO_JSVAL(BUILD_JSVAL(JSVAL_TAG_NULL,      0));
-const jsval JSVAL_ZERO  = IMPL_TO_JSVAL(BUILD_JSVAL(JSVAL_TAG_INT32,     0));
-const jsval JSVAL_ONE   = IMPL_TO_JSVAL(BUILD_JSVAL(JSVAL_TAG_INT32,     1));
-const jsval JSVAL_FALSE = IMPL_TO_JSVAL(BUILD_JSVAL(JSVAL_TAG_BOOLEAN,   false));
-const jsval JSVAL_TRUE  = IMPL_TO_JSVAL(BUILD_JSVAL(JSVAL_TAG_BOOLEAN,   true));
-const jsval JSVAL_VOID  = IMPL_TO_JSVAL(BUILD_JSVAL(JSVAL_TAG_UNDEFINED, 0));
-const HandleValue JS::NullHandleValue = HandleValue::fromMarkedLocation(&JSVAL_NULL);
-const HandleValue JS::UndefinedHandleValue = HandleValue::fromMarkedLocation(&JSVAL_VOID);
-
 const jsid voidIdValue = JSID_VOID;
 const jsid emptyIdValue = JSID_EMPTY;
 const HandleId JS::JSID_VOIDHANDLE = HandleId::fromMarkedLocation(&voidIdValue);
diff --git a/js/src/jsapi.h b/js/src/jsapi.h
index b27ee2c39621..b7e625aeca12 100644
--- a/js/src/jsapi.h
+++ b/js/src/jsapi.h
@@ -5087,9 +5087,6 @@ JS_DecodeInterpretedFunction(JSContext *cx, const void *data, uint32_t length,
 
 namespace JS {
 
-extern JS_PUBLIC_DATA(const Handle<Value>) NullHandleValue;
-extern JS_PUBLIC_DATA(const Handle<Value>) UndefinedHandleValue;
-
 extern JS_PUBLIC_DATA(const Handle<jsid>) JSID_VOIDHANDLE;
 extern JS_PUBLIC_DATA(const Handle<jsid>) JSID_EMPTYHANDLE;
 
diff --git a/js/src/jsfriendapi.cpp b/js/src/jsfriendapi.cpp
index a85fa6355664..ef25ca501246 100644
--- a/js/src/jsfriendapi.cpp
+++ b/js/src/jsfriendapi.cpp
@@ -991,24 +991,6 @@ js::GetEnterCompartmentDepth(JSContext *cx)
 }
 #endif
 
-JS_FRIEND_API(void)
-js::SetRuntimeProfilingStack(JSRuntime *rt, ProfileEntry *stack, uint32_t *size, uint32_t max)
-{
-    rt->spsProfiler.setProfilingStack(stack, size, max);
-}
-
-JS_FRIEND_API(void)
-js::EnableRuntimeProfilingStack(JSRuntime *rt, bool enabled)
-{
-    rt->spsProfiler.enable(enabled);
-}
-
-JS_FRIEND_API(jsbytecode*)
-js::ProfilingGetPC(JSRuntime *rt, JSScript *script, void *ip)
-{
-    return rt->spsProfiler.ipToPC(script, size_t(ip));
-}
-
 JS_FRIEND_API(void)
 js::SetDOMCallbacks(JSRuntime *rt, const DOMCallbacks *callbacks)
 {
diff --git a/js/src/jsfriendapi.h b/js/src/jsfriendapi.h
index b2b377880235..b76c3cf36319 100644
--- a/js/src/jsfriendapi.h
+++ b/js/src/jsfriendapi.h
@@ -669,84 +669,6 @@ GetPCCountScriptSummary(JSContext *cx, size_t script);
 JS_FRIEND_API(JSString *)
 GetPCCountScriptContents(JSContext *cx, size_t script);
 
-/*
- * A call stack can be specified to the JS engine such that all JS entry/exits
- * to functions push/pop an entry to/from the specified stack.
- *
- * For more detailed information, see vm/SPSProfiler.h
- */
-class ProfileEntry
-{
-    /*
-     * All fields are marked volatile to prevent the compiler from re-ordering
-     * instructions. Namely this sequence:
-     *
-     *    entry[size] = ...;
-     *    size++;
-     *
-     * If the size modification were somehow reordered before the stores, then
-     * if a sample were taken it would be examining bogus information.
-     *
-     * A ProfileEntry represents both a C++ profile entry and a JS one. Both use
-     * the string as a description, but JS uses the sp as NULL to indicate that
-     * it is a JS entry. The script_ is then only ever examined for a JS entry,
-     * and the idx is used by both, but with different meanings.
-     */
-    const char * volatile string; // Descriptive string of this entry
-    void * volatile sp;           // Relevant stack pointer for the entry
-    JSScript * volatile script_;  // if js(), non-null script which is running
-    int32_t volatile idx;         // if js(), idx of pc, otherwise line number
-
-  public:
-    /*
-     * All of these methods are marked with the 'volatile' keyword because SPS's
-     * representation of the stack is stored such that all ProfileEntry
-     * instances are volatile. These methods would not be available unless they
-     * were marked as volatile as well
-     */
-
-    bool js() volatile {
-        JS_ASSERT_IF(sp == NULL, script_ != NULL);
-        return sp == NULL;
-    }
-
-    uint32_t line() volatile { JS_ASSERT(!js()); return idx; }
-    JSScript *script() volatile { JS_ASSERT(js()); return script_; }
-    void *stackAddress() volatile { return sp; }
-    const char *label() volatile { return string; }
-
-    void setLine(uint32_t aLine) volatile { JS_ASSERT(!js()); idx = aLine; }
-    void setLabel(const char *aString) volatile { string = aString; }
-    void setStackAddress(void *aSp) volatile { sp = aSp; }
-    void setScript(JSScript *aScript) volatile { script_ = aScript; }
-
-    /* we can't know the layout of JSScript, so look in vm/SPSProfiler.cpp */
-    JS_FRIEND_API(jsbytecode *) pc() volatile;
-    JS_FRIEND_API(void) setPC(jsbytecode *pc) volatile;
-
-    static size_t offsetOfString() { return offsetof(ProfileEntry, string); }
-    static size_t offsetOfStackAddress() { return offsetof(ProfileEntry, sp); }
-    static size_t offsetOfPCIdx() { return offsetof(ProfileEntry, idx); }
-    static size_t offsetOfScript() { return offsetof(ProfileEntry, script_); }
-
-    /*
-     * The index used in the entry can either be a line number or the offset of
-     * a pc into a script's code. To signify a NULL pc, use a -1 index. This is
-     * checked against in pc() and setPC() to set/get the right pc.
-     */
-    static const int32_t NullPCIndex = -1;
-};
-
-JS_FRIEND_API(void)
-SetRuntimeProfilingStack(JSRuntime *rt, ProfileEntry *stack, uint32_t *size,
-                         uint32_t max);
-
-JS_FRIEND_API(void)
-EnableRuntimeProfilingStack(JSRuntime *rt, bool enabled);
-
-JS_FRIEND_API(jsbytecode*)
-ProfilingGetPC(JSRuntime *rt, JSScript *script, void *ip);
-
 #ifdef JS_THREADSAFE
 JS_FRIEND_API(bool)
 ContextHasOutstandingRequests(const JSContext *cx);
diff --git a/js/src/moz.build b/js/src/moz.build
index 2566a6964c84..87ee3b53a51a 100644
--- a/js/src/moz.build
+++ b/js/src/moz.build
@@ -68,6 +68,7 @@ EXPORTS.js += [
     '../public/HeapAPI.h',
     '../public/LegacyIntTypes.h',
     '../public/MemoryMetrics.h',
+    '../public/ProfilingStack.h',
     '../public/PropertyKey.h',
     '../public/RequiredDefines.h',
     '../public/RootingAPI.h',
@@ -132,6 +133,7 @@ CPP_SOURCES += [
     'TokenStream.cpp',
     'TypedArrayObject.cpp',
     'Unicode.cpp',
+    'Value.cpp',
     'Verifier.cpp',
     'Xdr.cpp',
     'YarrCanonicalizeUCS2.cpp',
diff --git a/js/src/vm/CharacterEncoding.cpp b/js/src/vm/CharacterEncoding.cpp
index 222caf14c08b..6e7a7f4ad17f 100644
--- a/js/src/vm/CharacterEncoding.cpp
+++ b/js/src/vm/CharacterEncoding.cpp
@@ -4,11 +4,11 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+#include "js/CharacterEncoding.h"
+
 #include "jscntxt.h"
 #include "jsprf.h"
 
-#include "js/CharacterEncoding.h"
-
 using namespace JS;
 
 Latin1CharsZ
diff --git a/js/src/vm/SPSProfiler.cpp b/js/src/vm/SPSProfiler.cpp
index 4d3723e92ff1..4dffb3976b33 100644
--- a/js/src/vm/SPSProfiler.cpp
+++ b/js/src/vm/SPSProfiler.cpp
@@ -265,14 +265,33 @@ SPSEntryMarker::~SPSEntryMarker()
 }
 
 JS_FRIEND_API(jsbytecode*)
-ProfileEntry::pc() volatile {
+ProfileEntry::pc() volatile
+{
     JS_ASSERT_IF(idx != NullPCIndex, idx >= 0 && uint32_t(idx) < script()->length);
     return idx == NullPCIndex ? NULL : script()->code + idx;
 }
 
 JS_FRIEND_API(void)
-ProfileEntry::setPC(jsbytecode *pc) volatile {
-    JS_ASSERT_IF(pc != NULL, script()->code <= pc &&
-                             pc < script()->code + script()->length);
+ProfileEntry::setPC(jsbytecode *pc) volatile
+{
+    JS_ASSERT_IF(pc != NULL, script()->code <= pc && pc < script()->code + script()->length);
     idx = pc == NULL ? NullPCIndex : pc - script()->code;
 }
+
+JS_FRIEND_API(void)
+js::SetRuntimeProfilingStack(JSRuntime *rt, ProfileEntry *stack, uint32_t *size, uint32_t max)
+{
+    rt->spsProfiler.setProfilingStack(stack, size, max);
+}
+
+JS_FRIEND_API(void)
+js::EnableRuntimeProfilingStack(JSRuntime *rt, bool enabled)
+{
+    rt->spsProfiler.enable(enabled);
+}
+
+JS_FRIEND_API(jsbytecode*)
+js::ProfilingGetPC(JSRuntime *rt, JSScript *script, void *ip)
+{
+    return rt->spsProfiler.ipToPC(script, size_t(ip));
+}
diff --git a/js/src/vm/SPSProfiler.h b/js/src/vm/SPSProfiler.h
index c8a1e345789e..224cd558da3a 100644
--- a/js/src/vm/SPSProfiler.h
+++ b/js/src/vm/SPSProfiler.h
@@ -14,6 +14,8 @@
 
 #include "jsscript.h"
 
+#include "js/ProfilingStack.h"
+
 /*
  * SPS Profiler integration with the JS Engine
  * https://developer.mozilla.org/en/Performance/Profiling_with_the_Built-in_Profiler
diff --git a/js/src/vm/Value.cpp b/js/src/vm/Value.cpp
new file mode 100644
index 000000000000..d88760b07600
--- /dev/null
+++ b/js/src/vm/Value.cpp
@@ -0,0 +1,21 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "js/Value.h"
+
+const jsval JSVAL_NULL  = IMPL_TO_JSVAL(BUILD_JSVAL(JSVAL_TAG_NULL,      0));
+const jsval JSVAL_ZERO  = IMPL_TO_JSVAL(BUILD_JSVAL(JSVAL_TAG_INT32,     0));
+const jsval JSVAL_ONE   = IMPL_TO_JSVAL(BUILD_JSVAL(JSVAL_TAG_INT32,     1));
+const jsval JSVAL_FALSE = IMPL_TO_JSVAL(BUILD_JSVAL(JSVAL_TAG_BOOLEAN,   false));
+const jsval JSVAL_TRUE  = IMPL_TO_JSVAL(BUILD_JSVAL(JSVAL_TAG_BOOLEAN,   true));
+const jsval JSVAL_VOID  = IMPL_TO_JSVAL(BUILD_JSVAL(JSVAL_TAG_UNDEFINED, 0));
+
+namespace JS {
+
+const HandleValue NullHandleValue = HandleValue::fromMarkedLocation(&JSVAL_NULL);
+const HandleValue UndefinedHandleValue = HandleValue::fromMarkedLocation(&JSVAL_VOID);
+
+} // namespace JS
diff --git a/js/xpconnect/public/nsAutoJSValHolder.h b/js/xpconnect/public/nsAutoJSValHolder.h
index 54fe8f3be880..4a737f33eee3 100644
--- a/js/xpconnect/public/nsAutoJSValHolder.h
+++ b/js/xpconnect/public/nsAutoJSValHolder.h
@@ -7,9 +7,10 @@
 #define __NSAUTOJSVALHOLDER_H__
 
 #include "nsDebug.h"
+#include "jsapi.h"
 
 /**
- * Simple class that looks and acts like a jsval except that it unroots
+ * Simple class that looks and acts like a JS::Value except that it unroots
  * itself automatically if Root() is ever called. Designed to be rooted on the
  * context or runtime (but not both!).
  */
@@ -44,7 +45,7 @@ public:
       else {
         this->Release();
       }
-      *this = static_cast<jsval>(aOther);
+      *this = static_cast<JS::Value>(aOther);
     }
     return *this;
   }
@@ -76,10 +77,10 @@ public:
 
   /**
    * Manually release, nullifying mVal, and mRt, but returning
-   * the original jsval.
+   * the original JS::Value.
    */
-  jsval Release() {
-    jsval oldval = mVal;
+  JS::Value Release() {
+    JS::Value oldval = mVal;
 
     if (mRt) {
       JS_RemoveValueRootRT(mRt, &mVal); // infallible
@@ -107,20 +108,20 @@ public:
          : nullptr;
   }
 
-  jsval* ToJSValPtr() {
+  JS::Value* ToJSValPtr() {
     return &mVal;
   }
 
   /**
-   * Pretend to be a jsval.
+   * Pretend to be a JS::Value.
    */
-  operator jsval() const { return mVal; }
+  operator JS::Value() const { return mVal; }
 
   nsAutoJSValHolder &operator=(JSObject* aOther) {
     return *this = OBJECT_TO_JSVAL(aOther);
   }
 
-  nsAutoJSValHolder &operator=(jsval aOther) {
+  nsAutoJSValHolder &operator=(JS::Value aOther) {
 #ifdef DEBUG
     if (JSVAL_IS_GCTHING(aOther) && !JSVAL_IS_NULL(aOther)) {
       MOZ_ASSERT(IsHeld(), "Not rooted!");
@@ -131,7 +132,7 @@ public:
   }
 
 private:
-  jsval mVal;
+  JS::Value mVal;
   JSRuntime* mRt;
 };
 
diff --git a/security/manager/ssl/src/nsNSSIOLayer.cpp b/security/manager/ssl/src/nsNSSIOLayer.cpp
index 6c42053ac1ad..41337b9985dd 100644
--- a/security/manager/ssl/src/nsNSSIOLayer.cpp
+++ b/security/manager/ssl/src/nsNSSIOLayer.cpp
@@ -7,6 +7,7 @@
 #include "nsNSSComponent.h"
 #include "nsNSSIOLayer.h"
 
+#include "mozilla/Casting.h"
 #include "mozilla/DebugOnly.h"
 #include "mozilla/Telemetry.h"
 
diff --git a/tools/profiler/PseudoStack.h b/tools/profiler/PseudoStack.h
index a59eb9937b01..66549bfec70c 100644
--- a/tools/profiler/PseudoStack.h
+++ b/tools/profiler/PseudoStack.h
@@ -8,7 +8,7 @@
 
 #include "mozilla/NullPtr.h"
 #include <stdint.h>
-#include "jsfriendapi.h"
+#include "js/ProfilingStack.h"
 #include <stdlib.h>
 #include <algorithm>