Use WindowActivated message instead of VisibilityChanged message to determine that Ash is the activ…

win8/metro_driver/chrome_app_view_ash.cc

Index: win8/metro_driver/chrome_app_view_ash.cc
diff --git a/win8/metro_driver/chrome_app_view_ash.cc b/win8/metro_driver/chrome_app_view_ash.cc
index e39118b8501f7b6aa6c7ba22c24dea92e1a8bfa2..3c00d9ece9eae740269286ca9a8cdbf59a6bd0c8 100644
--- a/win8/metro_driver/chrome_app_view_ash.cc
+++ b/win8/metro_driver/chrome_app_view_ash.cc
@@ -884,8 +884,13 @@ HRESULT ChromeAppViewAsh::OnVisibilityChanged(
   HRESULT hr = args->get_Visible(&visible);
   if (FAILED(hr))
     return hr;
-
-  ui_channel_->Send(new MetroViewerHostMsg_VisibilityChanged(!!visible));
+  // We used to send MetroViewerHostMsg_VisibilityChanged to the browser process
+  // upon receiving this message to catch when Ash gets activated, but it turned
+  // out that this wasn't sufficient as Ash can be visible yet a Chrome
+  // desktop window can be active in a multiple monitor scenario, resulting in
+  // Ash not being considered as reactivated when refocused (since this message
+  // was never received as the visibility didn't change). We switched to using
+  // OnWindowActivated() below to solve this problem.
   return S_OK;
 }
 
@@ -896,6 +901,14 @@ HRESULT ChromeAppViewAsh::OnWindowActivated(
   HRESULT hr = args->get_WindowActivationState(&state);
   if (FAILED(hr))
     return hr;
+
+  // Treat both full activation (Ash was reopened from the Start Screen or from
+  // any other Metro entry point in Windows) and pointer activation (user
+  // clicked back in Ash after using another app on another monitor) the same.
+  if (state == winui::Core::CoreWindowActivationState_CodeActivated ||
+      state == winui::Core::CoreWindowActivationState_PointerActivated) {
+    ui_channel_->Send(new MetroViewerHostMsg_WindowActivated());
+  }
   return S_OK;
 }