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

services/ui/surfaces/compositor_frame_sink.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 "services/ui/surfaces/compositor_frame_sink.h"
 
 #include "cc/output/copy_output_request.h"
 #include "cc/output/output_surface.h"
 #include "cc/output/renderer_settings.h"
 #include "cc/output/texture_mailbox_deleter.h"
@@ skipping 75 matching lines @@
       frame_sink_id_);
   display_compositor_->manager()->InvalidateFrameSinkId(frame_sink_id_);
 }
 
 void CompositorFrameSink::SubmitCompositorFrame(
     cc::CompositorFrame frame,
     const base::Callback<void()>& callback) {
   gfx::Size frame_size =
       frame.delegated_frame_data->render_pass_list.back()->output_rect.size();
   if (frame_size.IsEmpty() || frame_size != display_size_) {
-    if (!local_frame_id_.is_null())
+    if (local_frame_id_.is_valid())
       factory_.Destroy(local_frame_id_);
     local_frame_id_ = allocator_.GenerateId();
     factory_.Create(local_frame_id_);
     display_size_ = frame_size;
     display_->Resize(display_size_);
   }
   display_->SetSurfaceId(cc::SurfaceId(frame_sink_id_, local_frame_id_),
                          frame.metadata.device_scale_factor);
   factory_.SubmitCompositorFrame(local_frame_id_, std::move(frame), callback);
 }
@@ skipping 26 matching lines @@
 }
 
 void CompositorFrameSink::DisplayDidDrawAndSwap() {
   // This notification is not relevant to our client outside of tests. We
   // unblock the client from the DrawCallback when the surface is going to
   // be drawn.
 }
 
 }  // namespace surfaces
 }  // namespace ui