Blink handle selection handle visibility

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 30de9244e1f9f394e5109c14b6bb4f78b37dfbd6..a7fa0b4b3eec4272d2717ab1c205d4fa4afffced 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -767,7 +767,9 @@ static RenderPass* FindRenderPassById(const RenderPassList& list,
   return it == list.end() ? nullptr : it->get();
 }
 
-DrawResult LayerTreeHostImpl::CalculateRenderPasses(FrameData* frame) {
+DrawResult LayerTreeHostImpl::CalculateRenderPasses(
+    FrameData* frame,
+    bool handle_visibility_changed) {
   DCHECK(frame->render_passes.empty());
   DCHECK(CanDraw());
   DCHECK(!active_tree_->LayerListIsEmpty());
@@ -789,7 +791,13 @@ DrawResult LayerTreeHostImpl::CalculateRenderPasses(FrameData* frame) {
   if (root_surface_has_contributing_layers &&
       root_surface_has_no_visible_damage &&
       !active_tree_->property_trees()->effect_tree.HasCopyRequests() &&
-      !resources_must_be_resent && !hud_wants_to_draw_) {
+      !resources_must_be_resent && !hud_wants_to_draw_ &&
+      // When touch handle visibility changes there is no visible damage
+      // because touch handles are composited in the browser. However we
+      // still want the browser to be notified that the handles changed
+      // through the |ViewHostMsg_SwapCompositorFrame| IPC so we keep
+      // track of handle visibility changes through |handle_visibility_changed|.
+      !handle_visibility_changed) {
     TRACE_EVENT0("cc",
                  "LayerTreeHostImpl::CalculateRenderPasses::EmptyDamageRect");
     frame->has_no_damage = true;
@@ -1097,7 +1105,8 @@ DrawResult LayerTreeHostImpl::PrepareToDraw(FrameData* frame) {
         device_viewport_damage_rect);
   }
 
-  DrawResult draw_result = CalculateRenderPasses(frame);
+  DrawResult draw_result = CalculateRenderPasses(
+      frame, active_tree_->GetAndResetHandleVisibilityChanged());

[danakj, 2016/10/21 20:53:33]

can you call this from inside CalculateRenderPasses, and move the big comment
onto this call (which will store it in a local var there to be used below it in
the if statement)?

[amaralp, 2016/10/26 05:03:40]

Done

   if (draw_result != DRAW_SUCCESS) {
     DCHECK(!resourceless_software_draw_);
     return draw_result;