Add compositor support for half-float RGBA buffers and textures

cc/output/output_surface.cc

 // Copyright (c) 2013 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/output/output_surface.h"
 
 #include <stdint.h>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 18 matching lines @@
     : software_device_(std::move(software_device)) {
   DCHECK(software_device_);
 }
 
 OutputSurface::OutputSurface(
     scoped_refptr<VulkanContextProvider> vulkan_context_provider)
     : vulkan_context_provider_(std::move(vulkan_context_provider)) {
   DCHECK(vulkan_context_provider_);
 }
 
+bool OutputSurface::IsHighBitDepth() const {
+  return true;

[enne (OOO), 2017/02/01 23:55:22]

I'm a little surprised you return true by default here.  <_<

[ccameron, 2017/02/02 21:08:41]

I'm not 100% sure this is the right interface, so I've removed it and replaced
it with a TODO.

+}
+
 OutputSurface::~OutputSurface() = default;
 
 }  // namespace cc