android: Change OutputSurfaceWithoutParent max swaps to 1.

content/browser/renderer_host/compositor_impl_android.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/browser/renderer_host/compositor_impl_android.h"
 
 #include <android/bitmap.h>
 #include <android/native_window_jni.h>
 
 #include "base/android/jni_android.h"
@@ skipping 49 matching lines @@
 #include "third_party/khronos/GLES2/gl2ext.h"
 #include "third_party/skia/include/core/SkMallocPixelRef.h"
 #include "ui/android/window_android.h"
 #include "ui/gfx/android/device_display_info.h"
 #include "ui/gfx/swap_result.h"
 
 namespace content {
 
 namespace {
 
-const unsigned int kMaxSwapBuffers = 2U;
+const unsigned int kMaxSwapBuffers = 1U;
 
 // Used to override capabilities_.adjust_deadline_for_parent to false
 class OutputSurfaceWithoutParent : public cc::OutputSurface,
                                    public CompositorImpl::VSyncObserver {
  public:
   OutputSurfaceWithoutParent(
       CompositorImpl* compositor,
       const scoped_refptr<ContextProviderCommandBuffer>& context_provider,
       const base::Callback<void(gpu::Capabilities)>&
           populate_gpu_capabilities_callback)
       : cc::OutputSurface(context_provider),
         compositor_(compositor),
         populate_gpu_capabilities_callback_(populate_gpu_capabilities_callback),
         swap_buffers_completion_callback_(
             base::Bind(&OutputSurfaceWithoutParent::OnSwapBuffersCompleted,
                        base::Unretained(this))) {
     capabilities_.adjust_deadline_for_parent = false;
-    capabilities_.max_frames_pending = 2;
+    capabilities_.max_frames_pending = 1;

[no sievers, 2015/09/30 22:20:25]

nit: kMaxSwapBuffers?

[brianderson, 2015/10/01 00:20:12]

This refers to a different setting that will be used by cc::Display. I've added
a new kConstant for that in the latest patch.

   }
 
   ~OutputSurfaceWithoutParent() override { compositor_->RemoveObserver(this); }
 
   void SwapBuffers(cc::CompositorFrame* frame) override {
     GetCommandBufferProxy()->SetLatencyInfo(frame->metadata.latency_info);
     DCHECK(frame->gl_frame_data->sub_buffer_rect ==
            gfx::Rect(frame->gl_frame_data->size));
     context_provider_->ContextSupport()->Swap();
     client_->DidSwapBuffers();
@@ skipping 686 matching lines @@
 
 void CompositorImpl::SetNeedsAnimate() {
   needs_animate_ = true;
   if (!host_)
     return;
 
   host_->SetNeedsAnimate();
 }
 
 }  // namespace content