Bug 1420229 - Create a new components.css file and load it as a UA stylesheet;r=bz,Gijs

This provides a place for current XBL stylesheets to be loaded without using XBL <resources>,
that load as a UA sheet instead of loading them as document sheets. This makes the styles
apply more similarly to XBL, in that they are less specific than document styles.

MozReview-Commit-ID: 3ewomJZMbrk

layout/base/nsDocumentViewer.cpp

@@ -2438,6 +2438,12 @@ nsDocumentViewer::CreateStyleSet(nsIDocument* aDocument)
     }
 
     if (aDocument->LoadsFullXULStyleSheetUpFront()) {
+      // This is the only place components.css gets loaded, unlike xul.css
+      sheet = cache->XULComponentsSheet();
+      if (sheet) {
+        styleSet->PrependStyleSheet(SheetType::Agent, sheet);
+      }
+
       // nsXULElement::BindToTree loads xul.css on-demand if we don't load it
       // up-front here.
       sheet = cache->XULSheet();

layout/style/nsLayoutStylesheetCache.cpp

@@ -156,6 +156,17 @@ nsLayoutStylesheetCache::XULSheet()
   return mXULSheet;
 }
 
+StyleSheet*
+nsLayoutStylesheetCache::XULComponentsSheet()
+{
+  if (!mXULComponentsSheet) {
+    LoadSheetURL("chrome://global/content/components.css",
+                 &mXULComponentsSheet, eAgentSheetFeatures, eCrash);
+  }
+
+  return mXULComponentsSheet;
+}
+
 StyleSheet*
 nsLayoutStylesheetCache::QuirkSheet()
 {
@@ -313,6 +324,7 @@ nsLayoutStylesheetCache::SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf
   MEASURE(mUserChromeSheet);
   MEASURE(mUserContentSheet);
   MEASURE(mXULSheet);
+  MEASURE(mXULComponentsSheet);
 
   // Measurement of the following members may be added later if DMD finds it is
   // worthwhile:
@@ -353,6 +365,7 @@ nsLayoutStylesheetCache::nsLayoutStylesheetCache(StyleBackendType aType)
   if (XRE_IsParentProcess()) {
     // We know we need xul.css for the UI, so load that now too:
     XULSheet();
+    XULComponentsSheet();
   }
 
   auto& userContentSheetURL = aType == StyleBackendType::Gecko ?

layout/style/nsLayoutStylesheetCache.h

@@ -63,6 +63,7 @@ class nsLayoutStylesheetCache final
   mozilla::StyleSheet* HTMLSheet();
   mozilla::StyleSheet* MinimalXULSheet();
   mozilla::StyleSheet* XULSheet();
+  mozilla::StyleSheet* XULComponentsSheet();
   mozilla::StyleSheet* QuirkSheet();
   mozilla::StyleSheet* SVGSheet();
   mozilla::StyleSheet* MathMLSheet();
@@ -131,6 +132,7 @@ private:
   RefPtr<mozilla::StyleSheet> mUserChromeSheet;
   RefPtr<mozilla::StyleSheet> mUserContentSheet;
   RefPtr<mozilla::StyleSheet> mXULSheet;
+  RefPtr<mozilla::StyleSheet> mXULComponentsSheet;
 };
 
 #endif

toolkit/content/components.css

@@ -0,0 +1,9 @@
+/* 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/. */
+
+/* ===== components.css =================================================
+  == Styles ported from XBL <resources>, loaded as UA styles in every XUL doc
+  ======================================================================= */
+
+@import url("chrome://global/skin/menu.css");

toolkit/content/jar.mn

@@ -4,6 +4,7 @@ toolkit.jar:
    content/global/XPCNativeWrapper.js
    content/global/minimal-xul.css
 *  content/global/xul.css
+   content/global/components.css
    content/global/textbox.css
    content/global/menulist.css
    content/global/autocomplete.css

toolkit/themes/linux/global/global.css

@@ -8,7 +8,6 @@
 
 /* all localizable skin settings shall live here */
 @import url("chrome://global/locale/intl.css");
-@import url("chrome://global/skin/menu.css");
 
 @namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");
 

toolkit/themes/osx/global/global.css

@@ -4,7 +4,6 @@
 
 /* all localizable skin settings shall live here */
 @import url("chrome://global/locale/intl.css");
-@import url("chrome://global/skin/menu.css");
 
 %include shared.inc
 @namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");

toolkit/themes/windows/global/global.css

@@ -8,7 +8,6 @@
 
 /* all localizable skin settings shall live here */
 @import url("chrome://global/locale/intl.css");
-@import url("chrome://global/skin/menu.css");
 
 @namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");