Avoid rendering using GL in case damage rect is composited by overlay

cc/output/direct_renderer.cc

Index: cc/output/direct_renderer.cc
diff --git a/cc/output/direct_renderer.cc b/cc/output/direct_renderer.cc
index 1be41e9216244f7695506283ce4779778e768c79..3d2c2e417a3dc567d9b3a519b77d790d3a87afea 100644
--- a/cc/output/direct_renderer.cc
+++ b/cc/output/direct_renderer.cc
@@ -239,8 +239,18 @@ void DirectRenderer::DrawFrame(RenderPassList* render_passes_in_draw_order,
   // If we have any copy requests, we can't remove any quads for overlays,
   // otherwise the framebuffer will be missing the overlay contents.
   if (root_render_pass->copy_requests.empty()) {
+    bool needs_rendering = !frame.root_damage_rect.IsEmpty();
     overlay_processor_->ProcessForOverlays(
         resource_provider_, render_passes_in_draw_order, &frame.overlay_list);
+
+    // No need to render in case the damage rect is completely composited using
+    // overlays.
+    if (needs_rendering && frame.root_damage_rect.IsEmpty()) {

[piman, 2015/10/26 17:53:40]

Why the test for needs_rendering here?
Why would want to draw using GL instead if the root damage was empty before
ProcessForOverlays?

[kalyank, 2015/10/27 06:09:33]

Ya this wasn't needed, Fixed it. Added checks to make sure we don't have copy
requests for any of the RenderPass and damage rect is empty.

+      BindFramebufferToOutputSurface(&frame);
+      FinishDrawingFrame(&frame);
+      render_passes_in_draw_order->clear();
+      return;
+    }
   }
 
   for (size_t i = 0; i < render_passes_in_draw_order->size(); ++i) {