diff --git a/content/base/public/nsIFrameLoader.idl b/content/base/public/nsIFrameLoader.idl
index f17c97658de..0d1bc55a182 100644
--- a/content/base/public/nsIFrameLoader.idl
+++ b/content/base/public/nsIFrameLoader.idl
@@ -141,7 +141,7 @@ interface nsIContentViewManager : nsISupports
   readonly attribute nsIContentView rootContentView;
 };
 
-[scriptable, uuid(50a67436-bb44-11df-8d9a-001e37d2764a)]
+[scriptable, uuid(13c512d6-fba0-402a-9244-fe7941c43965)]
 interface nsIFrameLoader : nsISupports
 {
   /**
@@ -217,16 +217,23 @@ interface nsIFrameLoader : nsISupports
 
   attribute boolean delayRemoteDialogs;
 
+  /** 
+   * The default rendering mode is synchronous scrolling.  In this
+   * mode, it's an error to try to set a target viewport.
+   */
+  const unsigned long RENDER_MODE_DEFAULT        = 0x00000000;
 
   /**
-   * DEPRECATED. Please QI to nsIContentViewManager.
-   * FIXME 615368
+   * When asynchronous scrolling is enabled, a target viewport can be
+   * set to transform content pixels wrt its CSS viewport.
+   *
+   * NB: when async scrolling is enabled, it's the *user's*
+   * responsibility to update the target scroll offset.  In effect,
+   * the platform hands over control of scroll offset to the user.
    */
-  void scrollViewportTo(in float xPx, in float yPx);
-  void scrollViewportBy(in float dxPx, in float dyPx);
-  void setViewportScale(in float xScale, in float yScale);
-  readonly attribute float viewportScrollX;
-  readonly attribute float viewportScrollY;
+  const unsigned long RENDER_MODE_ASYNC_SCROLL   = 0x00000001;
+
+  attribute unsigned long renderMode;
 };
 
 native alreadyAddRefed_nsFrameLoader(already_AddRefed<nsFrameLoader>);
@@ -252,25 +259,3 @@ interface nsIFrameLoaderOwner : nsISupports
    */
   void swapFrameLoaders(in nsIFrameLoaderOwner aOtherOwner);
 };
-
-/** Please merge me into something else after 2.0 branches. */
-[scriptable, uuid(e3e2d3f8-1397-4984-abb3-435c29a1ca55)]
-interface nsIFrameLoader_MOZILLA_2_0_BRANCH : nsISupports
-{
-  /** 
-   * The default rendering mode is synchronous scrolling.  In this
-   * mode, it's an error to try to set a target viewport.
-   */
-  const unsigned long RENDER_MODE_DEFAULT        = 0x00000000;
-  /**
-   * When asynchronous scrolling is enabled, a target viewport can be
-   * set to transform content pixels wrt its CSS viewport.
-   *
-   * NB: when async scrolling is enabled, it's the *user's*
-   * responsibility to update the target scroll offset.  In effect,
-   * the platform hands over control of scroll offset to the user.
-   */
-  const unsigned long RENDER_MODE_ASYNC_SCROLL   = 0x00000001;
-
-  attribute unsigned long renderMode;
-};
diff --git a/content/base/src/nsFrameLoader.cpp b/content/base/src/nsFrameLoader.cpp
index 8922a726a22..f10ab414b47 100644
--- a/content/base/src/nsFrameLoader.cpp
+++ b/content/base/src/nsFrameLoader.cpp
@@ -310,7 +310,6 @@ NS_IMPL_CYCLE_COLLECTING_RELEASE_AMBIGUOUS(nsFrameLoader, nsIFrameLoader)
 
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsFrameLoader)
   NS_INTERFACE_MAP_ENTRY(nsIFrameLoader)
-  NS_INTERFACE_MAP_ENTRY(nsIFrameLoader_MOZILLA_2_0_BRANCH)
   NS_INTERFACE_MAP_ENTRY(nsIContentViewManager)
   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIFrameLoader)
 NS_INTERFACE_MAP_END
@@ -1684,36 +1683,6 @@ nsFrameLoader::UpdateBaseWindowPositionAndSize(nsIFrame *aIFrame)
   return NS_OK;
 }
 
-NS_IMETHODIMP
-nsFrameLoader::ScrollViewportTo(float aXpx, float aYpx)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
-NS_IMETHODIMP
-nsFrameLoader::ScrollViewportBy(float aDXpx, float aDYpx)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
-NS_IMETHODIMP
-nsFrameLoader::SetViewportScale(float aXScale, float aYScale)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
-NS_IMETHODIMP
-nsFrameLoader::GetViewportScrollX(float* aViewportScrollX)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
-NS_IMETHODIMP
-nsFrameLoader::GetViewportScrollY(float* aViewportScrollY)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
 NS_IMETHODIMP
 nsFrameLoader::GetRenderMode(PRUint32* aRenderMode)
 {
diff --git a/content/base/src/nsFrameLoader.h b/content/base/src/nsFrameLoader.h
index c34655a9e52..7df004da528 100644
--- a/content/base/src/nsFrameLoader.h
+++ b/content/base/src/nsFrameLoader.h
@@ -164,7 +164,6 @@ private:
 
 
 class nsFrameLoader : public nsIFrameLoader,
-                      public nsIFrameLoader_MOZILLA_2_0_BRANCH,
                       public nsIContentViewManager
 {
   friend class AutoResetInShow;
@@ -196,7 +195,6 @@ public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(nsFrameLoader, nsIFrameLoader)
   NS_DECL_NSIFRAMELOADER
-  NS_DECL_NSIFRAMELOADER_MOZILLA_2_0_BRANCH
   NS_DECL_NSICONTENTVIEWMANAGER
   NS_HIDDEN_(nsresult) CheckForRecursiveLoad(nsIURI* aURI);
   nsresult ReallyStartLoading();
diff --git a/layout/ipc/test-ipcbrowser-chrome.js b/layout/ipc/test-ipcbrowser-chrome.js
index dc1bb0558b3..f279ad4f886 100644
--- a/layout/ipc/test-ipcbrowser-chrome.js
+++ b/layout/ipc/test-ipcbrowser-chrome.js
@@ -22,9 +22,7 @@ function rootView() {
 }
 
 function enableAsyncScrolling() {
-    var i = Components.interfaces.nsIFrameLoader_MOZILLA_2_0_BRANCH;
-    var enabler = frameLoader().QueryInterface(i);
-    enabler.renderMode = i.RENDER_MODE_ASYNC_SCROLL;
+    frameLoader().renderMode = Components.interfaces.nsIFrameLoaer.RENDER_MODE_ASYNC_SCROLL;
 }
 
 // Functions affecting the content window.
diff --git a/layout/tools/reftest/reftest-content.js b/layout/tools/reftest/reftest-content.js
index 4b2abd2f69e..ddd735c1425 100644
--- a/layout/tools/reftest/reftest-content.js
+++ b/layout/tools/reftest/reftest-content.js
@@ -120,11 +120,6 @@ function windowUtils() {
                   .getInterface(CI.nsIDOMWindowUtils);
 }
 
-function windowUtils20() {
-    return windowUtils()
-               .QueryInterface(Components.interfaces.nsIDOMWindowUtils_MOZILLA_2_0_BRANCH);
-}
-
 function IDForEventTarget(event)
 {
     try {
@@ -258,7 +253,7 @@ function setupDisplayport(contentRootElement) {
     var dph = attrOrDefault("reftest-displayport-h", 0);
     if (dpw !== 0 || dph !== 0) {
         LogInfo("Setting displayport to <x=0, y=0, w="+ dpw +", h="+ dph +">");
-        windowUtils20().setDisplayPortForElement(0, 0, dpw, dph, content.document.documentElement);
+        windowUtils().setDisplayPortForElement(0, 0, dpw, dph, content.document.documentElement);
     }
 
     // XXX support resolution when needed