diff --git a/docshell/base/nsDocShellTreeOwner.cpp b/docshell/base/nsDocShellTreeOwner.cpp
index 8f5a85c89ee7..685ebc7d07ad 100644
--- a/docshell/base/nsDocShellTreeOwner.cpp
+++ b/docshell/base/nsDocShellTreeOwner.cpp
@@ -484,16 +484,6 @@ nsDocShellTreeOwner::GetPersistence(bool* aPersistPosition, bool* aPersistSize,
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 
-NS_IMETHODIMP
-nsDocShellTreeOwner::GetTabCount(uint32_t* aResult) {
-  if (mTreeOwner) {
-    return mTreeOwner->GetTabCount(aResult);
-  }
-
-  *aResult = 0;
-  return NS_OK;
-}
-
 NS_IMETHODIMP
 nsDocShellTreeOwner::GetHasPrimaryContent(bool* aResult) {
   *aResult = mPrimaryRemoteTab || mPrimaryContentShell;
diff --git a/docshell/base/nsIDocShellTreeOwner.idl b/docshell/base/nsIDocShellTreeOwner.idl
index d16257f8a128..d8efe98403eb 100644
--- a/docshell/base/nsIDocShellTreeOwner.idl
+++ b/docshell/base/nsIDocShellTreeOwner.idl
@@ -99,12 +99,6 @@ interface nsIDocShellTreeOwner : nsISupports
                           out boolean aPersistSize,
                           out boolean aPersistSizeMode);
 
-  /*
-  Gets the number of tabs currently open in our window, assuming
-  this tree owner has such a concept.
-  */
-  readonly attribute unsigned long tabCount;
-
   /*
   Returns true if there is a primary content shell or a primary
   remote tab.
diff --git a/toolkit/content/tests/chrome/findbar_window.xhtml b/toolkit/content/tests/chrome/findbar_window.xhtml
index 76bf1cae1337..c61f49b864d2 100644
--- a/toolkit/content/tests/chrome/findbar_window.xhtml
+++ b/toolkit/content/tests/chrome/findbar_window.xhtml
@@ -44,8 +44,6 @@
       setOverLink(aStatusText) {
         gStatusText = aStatusText;
       },
-
-      onBeforeLinkTraversal() { }
     };
 
     var SimpleTest = window.arguments[0].SimpleTest;
diff --git a/xpfe/appshell/AppWindow.cpp b/xpfe/appshell/AppWindow.cpp
index 8116ee6a9b99..912f97610c75 100644
--- a/xpfe/appshell/AppWindow.cpp
+++ b/xpfe/appshell/AppWindow.cpp
@@ -2582,15 +2582,6 @@ void AppWindow::SizeShellToWithLimit(int32_t aDesiredWidth,
   mDominantClientSize = true;
 }
 
-nsresult AppWindow::GetTabCount(uint32_t* aResult) {
-  if (mXULBrowserWindow) {
-    return mXULBrowserWindow->GetTabCount(aResult);
-  }
-
-  *aResult = 0;
-  return NS_OK;
-}
-
 nsresult AppWindow::GetInitialOpenWindowInfo(
     nsIOpenWindowInfo** aOpenWindowInfo) {
   NS_ENSURE_ARG_POINTER(aOpenWindowInfo);
diff --git a/xpfe/appshell/AppWindow.h b/xpfe/appshell/AppWindow.h
index c9cfc3650617..85b89f81e360 100644
--- a/xpfe/appshell/AppWindow.h
+++ b/xpfe/appshell/AppWindow.h
@@ -55,12 +55,12 @@ struct InitData;
 
 // AppWindow
 
-#define NS_APPWINDOW_IMPL_CID                        \
-  { /* 8eaec2f3-ed02-4be2-8e0f-342798477298 */       \
-    0x8eaec2f3, 0xed02, 0x4be2, {                    \
-      0x8e, 0x0f, 0x34, 0x27, 0x98, 0x47, 0x72, 0x98 \
-    }                                                \
-  }
+#define NS_APPWINDOW_IMPL_CID                 \
+  {/* 8eaec2f3-ed02-4be2-8e0f-342798477298 */ \
+   0x8eaec2f3,                                \
+   0xed02,                                    \
+   0x4be2,                                    \
+   {0x8e, 0x0f, 0x34, 0x27, 0x98, 0x47, 0x72, 0x98}}
 
 class nsContentShellInfo;
 
@@ -253,7 +253,6 @@ class AppWindow final : public nsIBaseWindow,
   enum PersistentAttributeUpdate { Sync, Async };
   void PersistentAttributesDirty(PersistentAttributes,
                                  PersistentAttributeUpdate);
-  nsresult GetTabCount(uint32_t* aResult);
 
   void LoadPersistentWindowState();
   nsresult GetPersistentValue(const nsAtom* aAttr, nsAString& aValue);
diff --git a/xpfe/appshell/nsChromeTreeOwner.cpp b/xpfe/appshell/nsChromeTreeOwner.cpp
index ad21380247bd..4b44eb352846 100644
--- a/xpfe/appshell/nsChromeTreeOwner.cpp
+++ b/xpfe/appshell/nsChromeTreeOwner.cpp
@@ -223,16 +223,6 @@ nsChromeTreeOwner::GetPersistence(bool* aPersistPosition, bool* aPersistSize,
   return NS_OK;
 }
 
-NS_IMETHODIMP
-nsChromeTreeOwner::GetTabCount(uint32_t* aResult) {
-  if (mAppWindow) {
-    return mAppWindow->GetTabCount(aResult);
-  }
-
-  *aResult = 0;
-  return NS_OK;
-}
-
 NS_IMETHODIMP
 nsChromeTreeOwner::GetHasPrimaryContent(bool* aResult) {
   NS_ENSURE_STATE(mAppWindow);
diff --git a/xpfe/appshell/nsContentTreeOwner.cpp b/xpfe/appshell/nsContentTreeOwner.cpp
index 3df0131ab700..c2ddf92f99e5 100644
--- a/xpfe/appshell/nsContentTreeOwner.cpp
+++ b/xpfe/appshell/nsContentTreeOwner.cpp
@@ -286,16 +286,6 @@ nsContentTreeOwner::GetPersistence(bool* aPersistPosition, bool* aPersistSize,
   return NS_OK;
 }
 
-NS_IMETHODIMP
-nsContentTreeOwner::GetTabCount(uint32_t* aResult) {
-  if (mAppWindow) {
-    return mAppWindow->GetTabCount(aResult);
-  }
-
-  *aResult = 0;
-  return NS_OK;
-}
-
 NS_IMETHODIMP
 nsContentTreeOwner::GetHasPrimaryContent(bool* aResult) {
   NS_ENSURE_STATE(mAppWindow);
diff --git a/xpfe/appshell/nsIXULBrowserWindow.idl b/xpfe/appshell/nsIXULBrowserWindow.idl
index 9adb4dd5a1dd..17093ddcafdb 100644
--- a/xpfe/appshell/nsIXULBrowserWindow.idl
+++ b/xpfe/appshell/nsIXULBrowserWindow.idl
@@ -34,14 +34,6 @@ interface nsIXULBrowserWindow : nsISupports
    */
   void setOverLink(in AString link);
 
-  /**
-   * Determines the appropriate target for a link.
-   */
-  AString onBeforeLinkTraversal(in AString originalTarget,
-                                in nsIURI linkURI,
-                                in Node linkNode,
-                                in boolean isAppTab);
-
   /**
    * Show/hide a tooltip (when the user mouses over a link, say).
    *
@@ -50,9 +42,4 @@ interface nsIXULBrowserWindow : nsISupports
   void showTooltip(in long x, in long y, in AString tooltip, in AString direction,
                    in Element browser);
   void hideTooltip();
-
-  /**
-   * Return the number of tabs in this window.
-   */
-  uint32_t getTabCount();
 };