Make commit for swap promises do not set can_cancel_commit.

content/renderer/render_widget.cc

 // Copyright (c) 2012 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/renderer/render_widget.h"
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/logging.h"
@@ skipping 1422 matching lines @@
 
   scoped_ptr<cc::SwapPromise> swap_promise =
       QueueMessageImpl(msg,
                        policy,
                        frame_swap_message_queue_.get(),
                        RenderThreadImpl::current()->sync_message_filter(),
                        compositor_->GetSourceFrameNumber());
 
   if (swap_promise) {
     compositor_->QueueSwapPromise(swap_promise.Pass());
-    compositor_->SetNeedsCommit();
+    // Request a commit. This might either A) request a commit ahead of time
+    // or B) request a commit which is not needed because there are not
+    // pending updates. If B) then the commit will be skipped and the swap
+    // promises will be broken (see EarlyOut_NoUpdates). To achieve that we
+    // call SetNeedsUpdateLayers instead of SetNeedsCommit so that
+    // can_cancel_commit is not unset.
+    compositor_->SetNeedsUpdateLayers();
   }
 }
 
 void RenderWidget::didCommitAndDrawCompositorFrame() {
   // NOTE: Tests may break if this event is renamed or moved. See
   // tab_capture_performancetest.cc.
   TRACE_EVENT0("gpu", "RenderWidget::didCommitAndDrawCompositorFrame");
   // Notify subclasses that we initiated the paint operation.
   DidInitiatePaint();
 }
@@ skipping 957 matching lines @@
 void RenderWidget::RegisterVideoHoleFrame(RenderFrameImpl* frame) {
   video_hole_frames_.AddObserver(frame);
 }
 
 void RenderWidget::UnregisterVideoHoleFrame(RenderFrameImpl* frame) {
   video_hole_frames_.RemoveObserver(frame);
 }
 #endif  // defined(VIDEO_HOLE)
 
 }  // namespace content