Bug 1472140 - 1. Set first paint flag when resuming and resizing composition; r=rbarker

When resuming composition in a new GeckoView, we wait for the first
paint signal in order to uncover the SurfaceView. This patch makes sure
that we always send the first paint signal.

MozReview-Commit-ID: EZeOR80d8HY

--HG--
extra : rebase_source : f82ab94ef87e5b0651f368918e8cd8a97469c68e

gfx/layers/ipc/UiCompositorControllerParent.cpp

@@ -74,6 +74,8 @@ UiCompositorControllerParent::RecvResumeAndResize(const int32_t& aWidth,
 {
   CompositorBridgeParent* parent = CompositorBridgeParent::GetCompositorBridgeParentFromLayersId(mRootLayerTreeId);
   if (parent) {
+    // Front-end expects a first paint callback upon resume/resize.
+    parent->RecvForceIsFirstPaint();
     parent->ResumeCompositionAndResize(aWidth, aHeight);
   }
   return IPC_OK();

mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoView.java

@@ -208,6 +208,9 @@ public class GeckoView extends FrameLayout {
             return null;
         }
 
+        // Cover the view while we are not drawing to the surface.
+        coverUntilFirstPaint(Color.WHITE);
+
         GeckoSession session = mSession;
         mSession.releaseDisplay(mDisplay.release());
         mSession.getOverscrollEdgeEffect().setInvalidationCallback(null);

widget/android/nsWindow.cpp

@@ -1264,11 +1264,6 @@ nsWindow::GeckoViewSupport::Transfer(const GeckoSession::Window::LocalRef& inst,
             [compositor = LayerSession::Compositor::GlobalRef(compositor)] {
                 compositor->OnCompositorAttached();
             });
-
-    // Set the first-paint flag so that we refresh viewports, etc.
-    if (RefPtr<CompositorBridgeChild> bridge = window.GetCompositorBridgeChild()) {
-        bridge->SendForceIsFirstPaint();
-    }
 }
 
 void