Centralize FrameSinkId allocation in one place

content/browser/renderer_host/context_provider_factory_impl_android.cc

Index: content/browser/renderer_host/context_provider_factory_impl_android.cc
diff --git a/content/browser/renderer_host/context_provider_factory_impl_android.cc b/content/browser/renderer_host/context_provider_factory_impl_android.cc
index 2437ca8146246f27cccb170c615d5f4cffafa755..08b8464ba3d8fff8ab9cf37dd63f85c105753588 100644
--- a/content/browser/renderer_host/context_provider_factory_impl_android.cc
+++ b/content/browser/renderer_host/context_provider_factory_impl_android.cc
@@ -66,7 +66,9 @@ ContextProviderFactoryImpl::ContextProviderFactoryImpl(
     : gpu_channel_factory_(gpu_channel_factory),
       in_handle_pending_requests_(false),
       in_shutdown_(false),
-      next_sink_id_(1u),
+      frame_sink_id_allocator_(
+          0 /* client_id, not to conflict with the client_id
+                                   generated from RenderWidgetHostImpl */),
       weak_factory_(this) {
   DCHECK(gpu_channel_factory_);
 }
@@ -136,12 +138,7 @@ cc::SurfaceManager* ContextProviderFactoryImpl::GetSurfaceManager() {
 }
 
 cc::FrameSinkId ContextProviderFactoryImpl::AllocateFrameSinkId() {
-  // The FrameSinkId generated here must be unique with
-  // RenderWidgetHostViewAndroid's
-  // FrameSinkId allocation.
-  // TODO(crbug.com/685777): Centralize allocation in one place for easier
-  // maintenance.
-  return cc::FrameSinkId(0 /* client_id */, next_sink_id_++);
+  return frame_sink_id_allocator_.NextFrameSinkId();
 }
 
 gpu::GpuMemoryBufferManager*