Add OnDisplayMetricsChanged in DisplayObserver.

media/video/capture/linux/video_capture_device_chromeos.cc

Index: media/video/capture/linux/video_capture_device_chromeos.cc
diff --git a/media/video/capture/linux/video_capture_device_chromeos.cc b/media/video/capture/linux/video_capture_device_chromeos.cc
index 40e6eaacfd6204f66f71771808353017558c1281..37eed372ecbedf1b8cf8901f206a307d77292f39 100644
--- a/media/video/capture/linux/video_capture_device_chromeos.cc
+++ b/media/video/capture/linux/video_capture_device_chromeos.cc
@@ -45,13 +45,15 @@ class VideoCaptureDeviceChromeOS::ScreenObserverDelegate
     DCHECK(!capture_device_);
   }
 
-  // gfx::DisplayObserver:
-  virtual void OnDisplayBoundsChanged(const gfx::Display& display) OVERRIDE {
-    SendDisplayRotation(display);
-  }
-
   virtual void OnDisplayAdded(const gfx::Display& /*new_display*/) OVERRIDE {}
   virtual void OnDisplayRemoved(const gfx::Display& /*old_display*/) OVERRIDE {}
+  virtual void OnDisplayMetricsChanged(
+      const gfx::Display& display,
+      gfx::DisplayObserver::DisplayMetrics metrics) OVERRIDE {
+    if (!(metrics & DISPLAY_METRIC_ROTATION))
+      return;
+    SendDisplayRotation(display);
+  }
 
   void AddObserverOnUIThread() {
     DCHECK(ui_task_runner_->BelongsToCurrentThread());