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

services/ui/ws/server_window_surface.h

 // 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.
 
 #ifndef SERVICES_UI_WS_SERVER_WINDOW_SURFACE_H_
 #define SERVICES_UI_WS_SERVER_WINDOW_SURFACE_H_
 
 #include <set>
 
 #include "base/macros.h"
@@ skipping 45 matching lines @@
   // one FrameSink per ServerWindowSurface, it allows the window server
   // to uniquely identify the window, and the thus the client that generated the
   // frame.
   const cc::FrameSinkId& frame_sink_id() const { return frame_sink_id_; }
 
   // The LocalFrameId can be thought of as an identifier to a bucket of
   // sequentially submitted CompositorFrames in the same FrameSink all sharing
   // the same size and device scale factor.
   const cc::LocalFrameId& local_frame_id() const { return local_frame_id_; }
 
-  bool has_frame() const { return !local_frame_id_.is_null(); }
+  bool has_frame() const { return local_frame_id_.is_valid(); }
 
   cc::SurfaceId GetSurfaceId() const;
 
   // Creates a surface dependency token that expires when this
   // ServerWindowSurface goes away.
   cc::SurfaceSequence CreateSurfaceSequence();
 
   ServerWindow* window();
 
  private:
@@ skipping 19 matching lines @@
   bool may_contain_video_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(ServerWindowSurface);
 };
 
 }  // namespace ws
 
 }  // namespace ui
 
 #endif  // SERVICES_UI_WS_SERVER_WINDOW_SURFACE_H_