Display skips swapping if overlays draw the damage

content/browser/renderer_host/compositor_impl_android.cc

Index: content/browser/renderer_host/compositor_impl_android.cc
diff --git a/content/browser/renderer_host/compositor_impl_android.cc b/content/browser/renderer_host/compositor_impl_android.cc
index 3f2ee6408a78d205be1a704ae2ae865a8493fa8a..e618c200388f3767db73d1af8682e4419ffb7e69 100644
--- a/content/browser/renderer_host/compositor_impl_android.cc
+++ b/content/browser/renderer_host/compositor_impl_android.cc
@@ -94,10 +94,16 @@ class OutputSurfaceWithoutParent : public cc::OutputSurface,
 
   void SwapBuffers(cc::CompositorFrame* frame) override {
     GetCommandBufferProxy()->SetLatencyInfo(frame->metadata.latency_info);
-    DCHECK(frame->gl_frame_data->sub_buffer_rect ==
-           gfx::Rect(frame->gl_frame_data->size));
-    context_provider_->ContextSupport()->Swap();
-    client_->DidSwapBuffers();
+    // Partial swap is not supported, so if the |sub_buffer_rect| is non-empty
+    // swap the whole buffer. Otherwise, there is no damage, so don't
+    // swap at all.
+    if (!frame->gl_frame_data->sub_buffer_rect.IsEmpty()) {
+      context_provider_->ContextSupport()->Swap();
+      client_->DidSwapBuffers();
+    } else {
+      client_->DidSwapBuffers();
+      OutputSurface::OnSwapBuffersComplete();
+    }
   }
 
   bool BindToClient(cc::OutputSurfaceClient* client) override {