Fix Ash on Windows multi-monitor support and snap-view sizing.

win8/metro_driver/chrome_app_view_ash.h

Index: win8/metro_driver/chrome_app_view_ash.h
diff --git a/win8/metro_driver/chrome_app_view_ash.h b/win8/metro_driver/chrome_app_view_ash.h
index 0989cda8a12e9ca57730de3435554b8c385596dc..010f0d6efac48561ca5e2f364a9b6d267b855745 100644
--- a/win8/metro_driver/chrome_app_view_ash.h
+++ b/win8/metro_driver/chrome_app_view_ash.h
@@ -111,6 +111,9 @@ class ChromeAppViewAsh
   HRESULT OnWindowActivated(winui::Core::ICoreWindow* sender,
                             winui::Core::IWindowActivatedEventArgs* args);
 
+  HRESULT OnSizeChanged(winui::Core::ICoreWindow* sender,
+                        winui::Core::IWindowSizeChangedEventArgs* args);
+
   mswr::ComPtr<winui::Core::ICoreWindow> window_;
   mswr::ComPtr<winapp::Core::ICoreApplicationView> view_;
   EventRegistrationToken activated_token_;
@@ -125,6 +128,7 @@ class ChromeAppViewAsh
   EventRegistrationToken accel_keydown_token_;
   EventRegistrationToken accel_keyup_token_;
   EventRegistrationToken window_activated_token_;
+  EventRegistrationToken sizechange_token_;
 
   // Keep state about which button is currently down, if any, as PointerMoved
   // events do not contain that state, but Ash's MouseEvents need it.