Set windows to be fully opaque upon leaving overview mode in Athena

athena/wm/window_overview_mode.cc

Index: athena/wm/window_overview_mode.cc
diff --git a/athena/wm/window_overview_mode.cc b/athena/wm/window_overview_mode.cc
index b34991cf82d7a7341ac17c77d016f1cda20e0dc9..90c7c5804c7739113c5b91d50b163827935e0a50 100644
--- a/athena/wm/window_overview_mode.cc
+++ b/athena/wm/window_overview_mode.cc
@@ -95,6 +95,10 @@ void RestoreWindowState(aura::Window* window,
       base::Bind(&HideWindowIfNotVisible, window, split_view_controller)));
 
   window->SetTransform(gfx::Transform());
+
+  // Reset the window opacity in case the user is dragging a window.
+  window->layer()->SetOpacity(1.0f);
+
   wm::SetShadowType(window, wm::SHADOW_TYPE_NONE);
 }