Enqueuing new frames in a Surface should cause Displays to reaggregate it

content/browser/compositor/delegated_frame_host.cc

Index: content/browser/compositor/delegated_frame_host.cc
diff --git a/content/browser/compositor/delegated_frame_host.cc b/content/browser/compositor/delegated_frame_host.cc
index 09b1c27ff62deed054900d045005952664b4b0fe..cc531bb841cdd59aeef139e18fd331e5db11a39a 100644
--- a/content/browser/compositor/delegated_frame_host.cc
+++ b/content/browser/compositor/delegated_frame_host.cc
@@ -343,9 +343,11 @@ void DelegatedFrameHost::SwapDelegatedFrame(
     }
     last_output_surface_id_ = output_surface_id;
   }
+  bool modified_layers = false;
   if (frame_size.IsEmpty()) {
     DCHECK(frame_data->resource_list.empty());
     EvictDelegatedFrame();
+    modified_layers = true;
   } else {
     if (use_surfaces_) {
       if (!surface_factory_) {
@@ -358,11 +360,12 @@ void DelegatedFrameHost::SwapDelegatedFrame(
       if (surface_id_.is_null() || frame_size != current_surface_size_ ||
           frame_size_in_dip != current_frame_size_in_dip_) {
         if (!surface_id_.is_null())
-          surface_factory_->Destroy(surface_id_);
+          surfaces_to_destroy_after_commit_.push_back(surface_id_);
         surface_id_ = id_allocator_->GenerateId();
         surface_factory_->Create(surface_id_, frame_size);
         client_->GetLayer()->SetShowSurface(surface_id_, frame_size_in_dip);
         current_surface_size_ = frame_size;
+        modified_layers = true;
       }
       scoped_ptr<cc::CompositorFrame> compositor_frame =
           make_scoped_ptr(new cc::CompositorFrame());
@@ -388,18 +391,23 @@ void DelegatedFrameHost::SwapDelegatedFrame(
       } else {
         frame_provider_->SetFrameData(frame_data.Pass());
       }
+      modified_layers = true;
     }
   }
   released_front_lock_ = NULL;
   current_frame_size_in_dip_ = frame_size_in_dip;
   CheckResizeLock();
 
-  client_->SchedulePaintInRect(damage_rect_in_dip);
+  if (modified_layers) {
+    // TODO(jbauman): Need to always tell the window observer about the
+    // damage.
+    client_->SchedulePaintInRect(damage_rect_in_dip);
+  }
 
   pending_delegated_ack_count_++;
 
   ui::Compositor* compositor = client_->GetCompositor();
-  if (!compositor) {
+  if (!compositor || !modified_layers) {
     SendDelegatedFrameAck(output_surface_id);
   } else {
     std::vector<ui::LatencyInfo>::const_iterator it;
@@ -479,7 +487,7 @@ void DelegatedFrameHost::EvictDelegatedFrame() {
   client_->GetLayer()->SetShowPaintedContent();
   frame_provider_ = NULL;
   if (!surface_id_.is_null()) {
-    surface_factory_->Destroy(surface_id_);
+    surfaces_to_destroy_after_commit_.push_back(surface_id_);
     surface_id_ = cc::SurfaceId();
   }
   delegated_frame_evictor_->DiscardedFrame();
@@ -767,6 +775,10 @@ void DelegatedFrameHost::CopyFromCompositingSurfaceHasResultForVideo(
 
 void DelegatedFrameHost::OnCompositingDidCommit(
     ui::Compositor* compositor) {
+  std::copy(surfaces_to_destroy_after_commit_.begin(),
+            surfaces_to_destroy_after_commit_.end(),
+            std::back_inserter(surfaces_to_destroy_after_swap_));
+  surfaces_to_destroy_after_commit_.clear();
   RenderWidgetHostImpl* host = client_->GetHost();
   if (can_lock_compositor_ == NO_PENDING_COMMIT) {
     can_lock_compositor_ = YES_CAN_LOCK;
@@ -792,6 +804,13 @@ void DelegatedFrameHost::OnCompositingStarted(
 
 void DelegatedFrameHost::OnCompositingEnded(
     ui::Compositor* compositor) {
+  for (std::vector<cc::SurfaceId>::iterator it =
+           surfaces_to_destroy_after_swap_.begin();
+       it != surfaces_to_destroy_after_swap_.end();
+       ++it) {
+    surface_factory_->Destroy(*it);
+  }
+  surfaces_to_destroy_after_swap_.clear();
 }
 
 void DelegatedFrameHost::OnCompositingAborted(ui::Compositor* compositor) {
@@ -837,6 +856,20 @@ DelegatedFrameHost::~DelegatedFrameHost() {
 
   if (!surface_id_.is_null())
     surface_factory_->Destroy(surface_id_);
+  for (std::vector<cc::SurfaceId>::iterator it =
+           surfaces_to_destroy_after_commit_.begin();
+       it != surfaces_to_destroy_after_commit_.end();
+       ++it) {
+    surface_factory_->Destroy(*it);
+  }
+  surfaces_to_destroy_after_commit_.clear();
+  for (std::vector<cc::SurfaceId>::iterator it =
+           surfaces_to_destroy_after_swap_.begin();
+       it != surfaces_to_destroy_after_swap_.end();
+       ++it) {
+    surface_factory_->Destroy(*it);
+  }
+  surfaces_to_destroy_after_swap_.clear();
   if (resource_collection_.get())
     resource_collection_->SetClient(NULL);