Replaced is_null() with is_valid in SurfaceId and related classes.

services/ui/ws/server_window_surface.cc

 // Copyright 2015 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 "services/ui/ws/server_window_surface.h"
 
 #include "base/callback.h"
 #include "base/message_loop/message_loop.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/quads/shared_quad_state.h"
@@ skipping 32 matching lines @@
   surface_manager->InvalidateFrameSinkId(frame_sink_id_);
 }
 
 void ServerWindowSurface::SubmitCompositorFrame(
     cc::CompositorFrame frame,
     const SubmitCompositorFrameCallback& callback) {
   gfx::Size frame_size =
       frame.delegated_frame_data->render_pass_list[0]->output_rect.size();
   // If the size of the CompostiorFrame has changed then destroy the existing
   // Surface and create a new one of the appropriate size.
-  if (local_frame_id_.is_null() || frame_size != last_submitted_frame_size_) {
-    if (!local_frame_id_.is_null())
+  if (!local_frame_id_.is_valid() || frame_size != last_submitted_frame_size_) {
+    if (local_frame_id_.is_valid())
       surface_factory_.Destroy(local_frame_id_);
     local_frame_id_ = surface_id_allocator_.GenerateId();
     surface_factory_.Create(local_frame_id_);
   }
   may_contain_video_ = frame.metadata.may_contain_video;
   surface_factory_.SubmitCompositorFrame(local_frame_id_, std::move(frame),
                                          callback);
   last_submitted_frame_size_ = frame_size;
   window()->delegate()->OnScheduleWindowPaint(window());
 }
 
 cc::SurfaceId ServerWindowSurface::GetSurfaceId() const {
-  if (local_frame_id_.is_null())
+  if (!local_frame_id_.is_valid())
     return cc::SurfaceId();
   return cc::SurfaceId(frame_sink_id_, local_frame_id_);
 }
 
 cc::SurfaceSequence ServerWindowSurface::CreateSurfaceSequence() {
   return surface_sequence_generator_.CreateSurfaceSequence();
 }
 
 ServerWindow* ServerWindowSurface::window() {
   return manager_->window();
 }
 
 void ServerWindowSurface::ReturnResources(
     const cc::ReturnedResourceArray& resources) {
   if (!client_ || !base::MessageLoop::current())
     return;
   client_->ReturnResources(mojo::Array<cc::ReturnedResource>::From(resources));
 }
 
 void ServerWindowSurface::SetBeginFrameSource(
     cc::BeginFrameSource* begin_frame_source) {
   // TODO(tansell): Implement this.
 }
 
 }  // namespace ws
 }  // namespace ui