[Win] Make drawAttention on shaped windows only flash taskbar icon.

ui/views/win/hwnd_message_handler.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/win/hwnd_message_handler.h"
 
 #include <dwmapi.h>
 #include <oleacc.h>
 #include <shellapi.h>
 #include <wtsapi32.h>
@@ skipping 716 matching lines @@
       SWP_FRAMECHANGED | SWP_NOACTIVATE | SWP_NOCOPYBITS |
       SWP_NOMOVE | SWP_NOOWNERZORDER | SWP_NOREPOSITION |
       SWP_NOSENDCHANGING | SWP_NOSIZE | SWP_NOZORDER);
 }
 
 void HWNDMessageHandler::FlashFrame(bool flash) {
   FLASHWINFO fwi;
   fwi.cbSize = sizeof(fwi);
   fwi.hwnd = hwnd();
   if (flash) {
-    fwi.dwFlags = FLASHW_ALL;
+    fwi.dwFlags = custom_window_region_ ? FLASHW_TRAY : FLASHW_ALL;
     fwi.uCount = 4;
     fwi.dwTimeout = 0;
   } else {
     fwi.dwFlags = FLASHW_STOP;
   }
   FlashWindowEx(&fwi);
 }
 
 void HWNDMessageHandler::ClearNativeFocus() {
   ::SetFocus(hwnd());
@@ skipping 1745 matching lines @@
     SetWindowPos(hwnd(), NULL, 0, 0, 0, 0, flags | SWP_HIDEWINDOW);
     SetWindowPos(hwnd(), NULL, 0, 0, 0, 0, flags | SWP_SHOWWINDOW);
   }
   // WM_DWMCOMPOSITIONCHANGED is only sent to top level windows, however we want
   // to notify our children too, since we can have MDI child windows who need to
   // update their appearance.
   EnumChildWindows(hwnd(), &SendDwmCompositionChanged, NULL);
 }
 
 }  // namespace views