Centralize FrameSinkId allocation in one place

android_webview/browser/surfaces_instance.cc

 // Copyright 2016 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 "android_webview/browser/surfaces_instance.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "android_webview/browser/aw_gl_surface.h"
@@ skipping 20 matching lines @@
 SurfacesInstance* g_surfaces_instance = nullptr;
 }  // namespace
 
 // static
 scoped_refptr<SurfacesInstance> SurfacesInstance::GetOrCreateInstance() {
   if (g_surfaces_instance)
     return make_scoped_refptr(g_surfaces_instance);
   return make_scoped_refptr(new SurfacesInstance);
 }
 
-SurfacesInstance::SurfacesInstance()
-    : next_client_id_(1u), frame_sink_id_(AllocateFrameSinkId()) {
+SurfacesInstance::SurfacesInstance() : frame_sink_id_(AllocateFrameSinkId()) {
   cc::RendererSettings settings;
 
   // Should be kept in sync with compositor_impl_android.cc.
   settings.allow_antialiasing = false;
   settings.highp_threshold_min = 2048;
 
   // Webview does not own the surface so should not clear it.
   settings.should_clear_root_render_pass = false;
 
   surface_manager_.reset(new cc::SurfaceManager);
@@ skipping 29 matching lines @@
   g_surfaces_instance = nullptr;
   DCHECK(child_ids_.empty());
 }
 
 void SurfacesInstance::DisplayOutputSurfaceLost() {
   // Android WebView does not handle context loss.
   LOG(FATAL) << "Render thread context loss";
 }
 
 cc::FrameSinkId SurfacesInstance::AllocateFrameSinkId() {
-  return cc::FrameSinkId(next_client_id_++, 0 /* sink_id */);
+  return frame_sink_id_allocator_.NextFrameSinkId();

[xlai (Olivia), 2017/02/15 18:05:46]

This particular change will change the behavior to 
cc::FrameSinkId(0, next_sink_id++);
I think this is a missed place from the last update.

[Fady Samuel, 2017/02/15 20:20:59]

Thanks for catching this, Olivia! :D

 }
 
 cc::SurfaceManager* SurfacesInstance::GetSurfaceManager() {
   return surface_manager_.get();
 }
 
 void SurfacesInstance::DrawAndSwap(const gfx::Size& viewport,
                                    const gfx::Rect& clip,
                                    const gfx::Transform& transform,
                                    const gfx::Size& frame_size,
@@ skipping 63 matching lines @@
 
 void SurfacesInstance::WillDrawSurface() {}
 
 void SurfacesInstance::ReclaimResources(
     const cc::ReturnedResourceArray& resources) {
   // Root surface should have no resources to return.
   CHECK(resources.empty());
 }
 
 }  // namespace android_webview