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

content/browser/renderer_host/render_widget_host_view_aura.cc

 // Copyright (c) 2012 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 "content/browser/renderer_host/render_widget_host_view_aura.h"
 
 #include <set>
 #include <utility>
 
 #include "base/auto_reset.h"
@@ skipping 2016 matching lines @@
   // |point| from DIPs to pixels before hittesting.
   gfx::Point point_in_pixels =
       gfx::ConvertPointToPixel(device_scale_factor_, point);
   cc::SurfaceId id = delegated_frame_host_->SurfaceIdAtPoint(
       delegate, point_in_pixels, transformed_point);
   *transformed_point =
       gfx::ConvertPointToDIP(device_scale_factor_, *transformed_point);
 
   // It is possible that the renderer has not yet produced a surface, in which
   // case we return our current namespace.
-  if (id.is_null())
+  if (!id.is_valid())
     return GetFrameSinkId();
   return id.frame_sink_id();
 }
 
 void RenderWidgetHostViewAura::ProcessMouseEvent(
     const blink::WebMouseEvent& event,
     const ui::LatencyInfo& latency) {
   host_->ForwardMouseEventWithLatencyInfo(event, latency);
 }
 
@@ skipping 1032 matching lines @@
           ->GetTextSelection(focused_view)
           ->GetSelectedText(&selected_text)) {
     // Set the CLIPBOARD_TYPE_SELECTION to the ui::Clipboard.
     ui::ScopedClipboardWriter clipboard_writer(ui::CLIPBOARD_TYPE_SELECTION);
     clipboard_writer.WriteText(selected_text);
   }
 #endif  // defined(USE_X11) && !defined(OS_CHROMEOS)
 }
 
 }  // namespace content