3 files changed, 14 insertions, 9 deletions
diff --git a/ui/aura/window.cc b/ui/aura/window.cc
index e5289e4..5c7007e 100644
--- a/ui/aura/window.cc
+++ b/ui/aura/window.cc
@@ -224,9 +224,9 @@ void Window::SetName(const std::string& name) {
 }
 
 void Window::SetTransparent(bool transparent) {
-  // Cannot change transparent flag after the window is initialized.
-  DCHECK(!layer());
   transparent_ = transparent;
+  if (layer())
+    layer_->SetFillsBoundsOpaquely(!transparent_);
 }
 
 RootWindow* Window::GetRootWindow() {
diff --git a/ui/views/widget/desktop_aura/desktop_root_window_host_win.cc b/ui/views/widget/desktop_aura/desktop_root_window_host_win.cc
index f04b90b..c2e2e88 100644
--- a/ui/views/widget/desktop_aura/desktop_root_window_host_win.cc
+++ b/ui/views/widget/desktop_aura/desktop_root_window_host_win.cc
@@ -122,13 +122,7 @@ aura::RootWindow* DesktopRootWindowHostWin::Init(
   rw_params.host = this;
   root_window_ = new aura::RootWindow(rw_params);
 
-  // TODO(beng): We probably need to move these two calls to some function that
-  //             can change depending on the native-ness of the frame. For right
-  //             now in the hack-n-slash days of win-aura, we can just
-  //             unilaterally turn this on.
-  root_window_->compositor()->SetHostHasTransparentBackground(true);
-  root_window_->SetTransparent(true);
-
+  SetWindowTransparency();
   root_window_->Init();
   root_window_->AddChild(content_window_);
 
@@ -344,6 +338,7 @@ bool DesktopRootWindowHostWin::ShouldUseNativeFrame() {
 
 void DesktopRootWindowHostWin::FrameTypeChanged() {
   message_handler_->FrameTypeChanged();
+  SetWindowTransparency();
 }
 
 NonClientFrameView* DesktopRootWindowHostWin::CreateNonClientFrameView() {
@@ -353,6 +348,7 @@ NonClientFrameView* DesktopRootWindowHostWin::CreateNonClientFrameView() {
 
 void DesktopRootWindowHostWin::SetFullscreen(bool fullscreen) {
   message_handler_->fullscreen_handler()->SetFullscreen(fullscreen);
+  SetWindowTransparency();
 }
 
 bool DesktopRootWindowHostWin::IsFullscreen() const {
@@ -412,6 +408,7 @@ void DesktopRootWindowHostWin::Hide() {
 }
 
 void DesktopRootWindowHostWin::ToggleFullScreen() {
+  SetWindowTransparency();
 }
 
 // GetBounds and SetBounds work in pixel coordinates, whereas other get/set
@@ -863,6 +860,12 @@ HWND DesktopRootWindowHostWin::GetHWND() const {
   return message_handler_->hwnd();
 }
 
+void DesktopRootWindowHostWin::SetWindowTransparency() {
+  bool transparent = ShouldUseNativeFrame() && !IsFullscreen();
+  root_window_->compositor()->SetHostHasTransparentBackground(transparent);
+  root_window_->SetTransparent(transparent);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // DesktopRootWindowHost, public:
 
diff --git a/ui/views/widget/desktop_aura/desktop_root_window_host_win.h b/ui/views/widget/desktop_aura/desktop_root_window_host_win.h
index 59e54d8..028e608 100644
--- a/ui/views/widget/desktop_aura/desktop_root_window_host_win.h
+++ b/ui/views/widget/desktop_aura/desktop_root_window_host_win.h
@@ -207,6 +207,8 @@ class VIEWS_EXPORT DesktopRootWindowHostWin
   HWND GetHWND() const;
 
  private:
+  void SetWindowTransparency();
+
   // We are owned by the RootWindow, but we have to have a back pointer to it.
   aura::RootWindow* root_window_;