import changes from `dev' branch of rmottola/Arctic-Fox:

- Bug 1172889 - Remove unused nsFrameLoader::DestroyChild. r=smaug (36bbb4447)
- Bug 1172889 - Remove unused nsFrameLoader::mContentParent. r=smaug (cee16d62f)
- Bug 1172889 - Get current RenderFrameParent from TabParent directly. r=roc (b7090504e)
- Bug 1176239, do tab navigation in the child when moving between the parent and child process, r=smaug (5c3d8213c)
- Bug 1125325 followup: Add missing 'override' keyword to TabChild::GetInnerSize() and nsWindowRoot::AddBrowser(), RemoveBrowser(), EnumerateBrowsers(). rs=ehsan (3ea24684f)
- reorder includes (d09953fd0)
- Bug 1190245 - Separate mMessageManager creation and FrameScript loading. r=smaug (90eaa1612)
- Bug 1177578 - Remove 'No docshells for remote frames' warning in nsFrameLoader::GetDocShell. r=smaug (de5770f1e)
- Bug 1164616 - "nsFrameLoader::DelayedStartLoadingRunnable is unused".  r=josh (2472ccba6)
- Bug 1172889 - Rename nsFrameLoader::GetCurrentRemoteFrame to nsFrameLoader::GetCurrentRenderFrame. r=roc (8563de171)
- Bug 1172889 - Reorder nsFrameLoader member declarations. r=smaug (535d6426d)
- Bug 1190245 - Make the MaybeCreateDocShell using code path easier to follow. r=smaug (0d96f4663)
- Bug 1190245 - Make frame script loading and browser-api initialization easier to follow. r=smaug (7993cfe00)

layout/ipc/RenderFrameParent.cpp

@@ -329,8 +329,6 @@ RenderFrameParent::RenderFrameParent(nsFrameLoader* aFrameLoader,
     mLayersId = *aId;
     CompositorChild::Get()->SendNotifyChildCreated(mLayersId);
   }
-  // Set a default RenderFrameParent
-  mFrameLoader->SetCurrentRemoteFrame(this);
   *aSuccess = true;
 }
 
@@ -445,15 +443,6 @@ RenderFrameParent::ActorDestroy(ActorDestroyReason why)
     }
   }
 
-  if (mFrameLoader && mFrameLoader->GetCurrentRemoteFrame() == this) {
-    // XXX this might cause some weird issues ... we'll just not
-    // redraw the part of the window covered by this until the "next"
-    // remote frame has a layer-tree transaction.  For
-    // why==NormalShutdown, we'll definitely want to do something
-    // better, especially as nothing guarantees another Update() from
-    // the "next" remote layer tree.
-    mFrameLoader->SetCurrentRemoteFrame(nullptr);
-  }
   mFrameLoader = nullptr;
 }
 
@@ -481,8 +470,6 @@ RenderFrameParent::RecvUpdateHitRegion(const nsRegion& aRegion)
 void
 RenderFrameParent::TriggerRepaint()
 {
-  mFrameLoader->SetCurrentRemoteFrame(this);
-
   nsIFrame* docFrame = mFrameLoader->GetPrimaryFrameOfOwningContent();
   if (!docFrame) {
     // Bad, but nothing we can do about it (XXX/cjones: or is there?