While dragging a window, show a semi-transparent aura window instead of the standard gray phantom wi

ash/wm/window_resizer.h

Index: ash/wm/window_resizer.h
diff --git a/ash/wm/window_resizer.h b/ash/wm/window_resizer.h
index 80ae948ee35e18a5950fef7b9559375d1fea66af..ab37ce52c43d3fb4bfc6572d130e9391898b5972 100644
--- a/ash/wm/window_resizer.h
+++ b/ash/wm/window_resizer.h
@@ -74,6 +74,9 @@ class ASH_EXPORT WindowResizer {
     // Location passed to the constructor, in |window->parent()|'s coordinates.
     gfx::Point initial_location_in_parent;
 
+    // Initial opacity of the window.
+    float initial_opacity;
+
     // The component the user pressed on.
     int window_component;