cc: Get rid of LayerTreeHost::output_surface_lost_ state.

cc/trees/proxy_main.cc

 // Copyright 2015 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 "cc/trees/proxy_main.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/trace_event/trace_event.h"
@@ skipping 141 matching lines @@
 
   if (!layer_tree_host_->visible()) {
     TRACE_EVENT_INSTANT0("cc", "EarlyOut_NotVisible", TRACE_EVENT_SCOPE_THREAD);
     std::vector<std::unique_ptr<SwapPromise>> empty_swap_promises;
     channel_main_->BeginMainFrameAbortedOnImpl(
         CommitEarlyOutReason::ABORTED_NOT_VISIBLE, begin_main_frame_start_time,
         std::move(empty_swap_promises));
     return;
   }
 
-  if (layer_tree_host_->output_surface_lost()) {

[enne (OOO), 2016/08/23 17:26:00]

Ohmygosh so glad to get rid of this conditional.

-    TRACE_EVENT_INSTANT0("cc", "EarlyOut_OutputSurfaceLost",
-                         TRACE_EVENT_SCOPE_THREAD);
-    std::vector<std::unique_ptr<SwapPromise>> empty_swap_promises;
-    channel_main_->BeginMainFrameAbortedOnImpl(
-        CommitEarlyOutReason::ABORTED_OUTPUT_SURFACE_LOST,
-        begin_main_frame_start_time, std::move(empty_swap_promises));
-    return;
-  }
-
   current_pipeline_stage_ = ANIMATE_PIPELINE_STAGE;
 
   layer_tree_host_->ApplyScrollAndScale(
       begin_main_frame_state->scroll_info.get());
 
   if (begin_main_frame_state->begin_frame_callbacks) {
     for (auto& callback : *begin_main_frame_state->begin_frame_callbacks)
       callback.Run();
   }
 
@@ skipping 217 matching lines @@
     CompletionEvent completion;
     channel_main_->MainFrameWillHappenOnImplForTesting(&completion,
                                                        &main_frame_will_happen);
     completion.Wait();
   }
   return main_frame_will_happen;
 }
 
 void ProxyMain::ReleaseOutputSurface() {
   DCHECK(IsMainThread());
-  DCHECK(layer_tree_host_->output_surface_lost());
-
   DebugScopedSetMainThreadBlocked main_thread_blocked(task_runner_provider_);
   CompletionEvent completion;
   channel_main_->ReleaseOutputSurfaceOnImpl(&completion);
   completion.Wait();
 }
 
 void ProxyMain::UpdateTopControlsState(TopControlsState constraints,
                                        TopControlsState current,
                                        bool animate) {
   DCHECK(IsMainThread());
@@ skipping 11 matching lines @@
     return false;
   channel_main_->SetNeedsCommitOnImpl();
   return true;
 }
 
 bool ProxyMain::IsMainThread() const {
   return task_runner_provider_->IsMainThread();
 }
 
 }  // namespace cc