Not submitted - Fixing invalid visibility states with layers which showed up in unittests ...

ash/wm/overview/window_selector_panels.cc

Index: ash/wm/overview/window_selector_panels.cc
diff --git a/ash/wm/overview/window_selector_panels.cc b/ash/wm/overview/window_selector_panels.cc
index 37d66871d5d6c763e284c77a5454f09fdbf54c90..f789567cf47b1eee1fd7f32b8d0509bd5a91afb6 100644
--- a/ash/wm/overview/window_selector_panels.cc
+++ b/ash/wm/overview/window_selector_panels.cc
@@ -58,7 +58,10 @@ ScopedTransformPanelWindow::~ScopedTransformPanelWindow() {
 
 void ScopedTransformPanelWindow::PrepareForOverview() {
   ScopedTransformOverviewWindow::PrepareForOverview();
-  GetCalloutWidget()->GetLayer()->SetOpacity(0.0f);
+  // The window is logically visible and we cannot make the layer fade to
+  // alpha=0. We therefore provide a float value which will result in a
+  // byte value of 0 but gets detected as not 0.
+  GetCalloutWidget()->GetLayer()->SetOpacity(0.001f);
 }
 
 views::Widget* ScopedTransformPanelWindow::GetCalloutWidget() {