Tiling priorities in Android Webview.

android_webview/browser/hardware_renderer.cc

Index: android_webview/browser/hardware_renderer.cc
diff --git a/android_webview/browser/hardware_renderer.cc b/android_webview/browser/hardware_renderer.cc
index 4ed2859b1399038a5dd060058b0bfcd450158404..4f2b5c2f78897fd0bd46d72deb87d6795fcc1289 100644
--- a/android_webview/browser/hardware_renderer.cc
+++ b/android_webview/browser/hardware_renderer.cc
@@ -207,6 +207,15 @@ void HardwareRenderer::DrawGL(bool stencil_enabled,
     layer_tree_host_->Composite(gfx::FrameTime::Now());
   }
   gl_surface_->ResetBackingFrameBufferObject();
+
+  // Need to post the new transform matrix back to child compositor because
+  // there is no onDraw during a Render Thread animation, and child compositor
+  // might not have the tiles rasterized as the animation goes on.
+  if (transform != transform_) {
+    transform_ = transform;
+    shared_renderer_state_->PostExternalDrawConstraintsToChildCompositor(
+        clip_, transform_);
+  }
 }
 
 scoped_ptr<cc::OutputSurface> HardwareRenderer::CreateOutputSurface(