Remove use of WS_EX_COMPOSITED for translucent windows.

content/browser/compositor/software_output_device_win.cc

 // Copyright 2014 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 "content/browser/compositor/software_output_device_win.h"
 
 #include "base/debug/alias.h"
 #include "base/memory/shared_memory.h"
 #include "cc/resources/shared_bitmap.h"
 #include "content/public/browser/browser_thread.h"
 #include "skia/ext/platform_canvas.h"
 #include "skia/ext/skia_utils_win.h"
+#include "ui/base/win/internal_constants.h"
 #include "ui/compositor/compositor.h"
 #include "ui/gfx/gdi_util.h"
 #include "ui/gfx/skia_util.h"
 
 namespace content {
 
 // If a window is larger than this in bytes, don't even try to create a
 // backing bitmap for it.
 static const size_t kMaxBitmapSizeBytes = 4 * (16384 * 8192);
 
@@ skipping 63 matching lines @@
 }
 
 SoftwareOutputDeviceWin::SoftwareOutputDeviceWin(OutputDeviceBacking* backing,
                                                  ui::Compositor* compositor)
     : hwnd_(compositor->widget()),
       is_hwnd_composited_(false),
       backing_(backing),
       in_paint_(false) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
-  LONG style = GetWindowLong(hwnd_, GWL_EXSTYLE);
-  is_hwnd_composited_ = !!(style & WS_EX_COMPOSITED);
+  is_hwnd_composited_ = !!::GetProp(hwnd_, ui::kWindowTranslucent);
   // Layered windows must be completely updated every time, so they can't
   // share contents with other windows.
   if (is_hwnd_composited_)
     backing_ = nullptr;
   if (backing_)
     backing_->RegisterOutputDevice(this);
 }
 
 SoftwareOutputDeviceWin::~SoftwareOutputDeviceWin() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
@@ skipping 62 matching lines @@
 
   if (is_hwnd_composited_) {
     RECT wr;
     GetWindowRect(hwnd_, &wr);
     SIZE size = {wr.right - wr.left, wr.bottom - wr.top};
     POINT position = {wr.left, wr.top};
     POINT zero = {0, 0};
     BLENDFUNCTION blend = {AC_SRC_OVER, 0x00, 0xFF, AC_SRC_ALPHA};
 
     DWORD style = GetWindowLong(hwnd_, GWL_EXSTYLE);
-    style &= ~WS_EX_COMPOSITED;
+    DCHECK(!(style & WS_EX_COMPOSITED));
     style |= WS_EX_LAYERED;
     SetWindowLong(hwnd_, GWL_EXSTYLE, style);
 
     ::UpdateLayeredWindow(hwnd_, NULL, &position, &size, dib_dc, &zero,
                           RGB(0xFF, 0xFF, 0xFF), &blend, ULW_ALPHA);
   } else {
     HDC hdc = ::GetDC(hwnd_);
     RECT src_rect = rect.ToRECT();
     skia::CopyHDC(dib_dc,
                   hdc,
                   rect.x(),
                   rect.y(),
                   contents_.get()->imageInfo().isOpaque(),
                   src_rect,
                   contents_.get()->getTotalMatrix());
 
     ::ReleaseDC(hwnd_, hdc);
   }
 }
 
 void SoftwareOutputDeviceWin::ReleaseContents() {
   DCHECK(!in_paint_);
   contents_.reset();
 }
 
 }  // namespace content