DelegatedFrameHost should not send immediate ack when compositor is null

content/browser/renderer_host/delegated_frame_host.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/delegated_frame_host.h"
 
 #include <algorithm>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 433 matching lines @@
       SendReclaimCompositorResources(last_compositor_frame_sink_id_,
                                      false /* is_swap_ack */);
     }
     last_compositor_frame_sink_id_ = compositor_frame_sink_id;
   }
   bool skip_frame = false;
   pending_delegated_ack_count_++;
 
   background_color_ = frame.metadata.root_background_color;
 
-  bool did_send_ack_callback = false;
   if (frame_size.IsEmpty()) {
     DCHECK(frame.resource_list.empty());
     EvictDelegatedFrame();
   } else {
     ImageTransportFactory* factory = ImageTransportFactory::GetInstance();
     cc::SurfaceManager* manager =
         factory->GetContextFactoryPrivate()->GetSurfaceManager();
     bool allocated_new_local_surface_id = false;
     if (!local_surface_id_.is_valid() || frame_size != current_surface_size_ ||
         frame_size_in_dip != current_frame_size_in_dip_) {
       local_surface_id_ = id_allocator_->GenerateId();
       allocated_new_local_surface_id = true;
     }
 
     gfx::Size desired_size = client_->DelegatedFrameHostDesiredSizeInDIP();
     if (desired_size != frame_size_in_dip && !desired_size.IsEmpty()) {
       skip_frame = true;
       skipped_latency_info_list_.insert(skipped_latency_info_list_.end(),
                                         frame.metadata.latency_info.begin(),
                                         frame.metadata.latency_info.end());
       frame.metadata.latency_info.clear();
     } else {
       frame.metadata.latency_info.insert(frame.metadata.latency_info.end(),
                                          skipped_latency_info_list_.begin(),
                                          skipped_latency_info_list_.end());
       skipped_latency_info_list_.clear();
     }
 
     cc::SurfaceFactory::DrawCallback ack_callback;
-    if (compositor_ && !skip_frame) {
+    if (!skip_frame) {
       ack_callback = base::Bind(&DelegatedFrameHost::SurfaceDrawn, AsWeakPtr(),
                                 compositor_frame_sink_id);
-      did_send_ack_callback = true;
     }
     surface_factory_->SubmitCompositorFrame(local_surface_id_, std::move(frame),
                                             ack_callback);
     if (allocated_new_local_surface_id) {
       // manager must outlive compositors using it.
       cc::SurfaceId surface_id(frame_sink_id_, local_surface_id_);
       cc::SurfaceInfo surface_info(surface_id, frame_device_scale_factor,
                                    frame_size);
       client_->DelegatedFrameHostGetLayer()->SetShowSurface(
           surface_info, manager->reference_factory());
       current_surface_size_ = frame_size;
       current_scale_factor_ = frame_device_scale_factor;
     }
   }
   released_front_lock_ = NULL;
   current_frame_size_in_dip_ = frame_size_in_dip;
   CheckResizeLock();
 
   UpdateGutters();
 
   if (!damage_rect_in_dip.IsEmpty()) {
     client_->DelegatedFrameHostGetLayer()->OnDelegatedFrameDamage(
         damage_rect_in_dip);
   }
 
-  // Note that |compositor_| may be reset by SetShowSurface or
-  // SetShowDelegatedContent above.
-  if (!compositor_ || skip_frame) {
+  if (skip_frame) {
     SendReclaimCompositorResources(compositor_frame_sink_id,
-                                   !did_send_ack_callback /* is_swap_ack */);
-  } else {
+                                   true /* is_swap_ack */);
+  }
+
+  if (compositor_ && !skip_frame)
     can_lock_compositor_ = NO_PENDING_COMMIT;
-  }
+
   if (local_surface_id_.is_valid()) {
     delegated_frame_evictor_->SwappedFrame(
         client_->DelegatedFrameHostIsVisible());
   }
   // Note: the frame may have been evicted immediately.
 }
 
 void DelegatedFrameHost::ClearDelegatedFrame() {
   if (local_surface_id_.is_valid())
     EvictDelegatedFrame();
@@ skipping 337 matching lines @@
         std::move(request));
   }
 }
 
 void DelegatedFrameHost::UnlockResources() {
   DCHECK(local_surface_id_.is_valid());
   delegated_frame_evictor_->UnlockFrame();
 }
 
 }  // namespace content