Make scoped dc objects smarter.

chrome/browser/ui/window_snapshot/window_snapshot_win.cc

 // Copyright (c) 2011 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 "chrome/browser/ui/window_snapshot/window_snapshot.h"
 
 #include "base/win/scoped_gdi_object.h"
 #include "base/win/scoped_hdc.h"
 #include "base/win/scoped_select_object.h"
 #include "ui/gfx/codec/png_codec.h"
@@ skipping 25 matching lines @@
   // Create a memory DC that's compatible with the window.
   HDC window_hdc = GetWindowDC(window_handle);
   base::win::ScopedCreateDC mem_hdc(CreateCompatibleDC(window_hdc));
 
   BITMAPINFOHEADER hdr;
   gfx::CreateBitmapHeader(snapshot_bounds.width(),
                           snapshot_bounds.height(),
                           &hdr);
   unsigned char *bit_ptr = NULL;
   base::win::ScopedBitmap bitmap(
-      CreateDIBSection(mem_hdc,
+      CreateDIBSection(mem_hdc.Get(),
                        reinterpret_cast<BITMAPINFO*>(&hdr),
                        DIB_RGB_COLORS,
                        reinterpret_cast<void **>(&bit_ptr),
                        NULL, 0));
 
-  base::win::ScopedSelectObject select_bitmap(mem_hdc, bitmap);
+  base::win::ScopedSelectObject select_bitmap(mem_hdc.Get(), bitmap);
   // Clear the bitmap to white (so that rounded corners on windows
   // show up on a white background, and strangely-shaped windows
   // look reasonable). Not capturing an alpha mask saves a
   // bit of space.
-  PatBlt(mem_hdc, 0, 0, snapshot_bounds.width(), snapshot_bounds.height(),
+  PatBlt(mem_hdc.Get(), 0, 0, snapshot_bounds.width(), snapshot_bounds.height(),
          WHITENESS);
-  // Grab a copy of the window
-  // First, see if PrintWindow is defined (it's not in Windows 2000).
-  typedef BOOL (WINAPI *PrintWindowPointer)(HWND, HDC, UINT);
-  PrintWindowPointer print_window =

[cpu_(ooo_6.6-7.5), 2012/02/08 00:03:20]

Removing win2k hack.

-      reinterpret_cast<PrintWindowPointer>(
-          GetProcAddress(GetModuleHandle(L"User32.dll"), "PrintWindow"));
 
-  // If PrintWindow is defined, use it.  It will work on partially
-  // obscured windows, and works better for out of process sub-windows.
-  // Otherwise grab the bits we can get with BitBlt; it's better
-  // than nothing and will work fine in the average case (window is
-  // completely on screen).
-  if (snapshot_bounds.origin() == gfx::Point() && print_window)
-    (*print_window)(window_handle, mem_hdc, 0);
-  else
-    BitBlt(mem_hdc, 0, 0, snapshot_bounds.width(), snapshot_bounds.height(),
-           window_hdc, snapshot_bounds.x(), snapshot_bounds.y(), SRCCOPY);
+  if (snapshot_bounds.origin() == gfx::Point()) {

[Peter Kasting, 2012/02/08 00:38:49]

Nit: If you reverse this conditional you can combine these nested ifs:

  if (origin != Point()) {
    BitBlt(...);
  } else if (!PrintWindow(...)) {
    NOTREACHED();
  }

[cpu_(ooo_6.6-7.5), 2012/02/10 19:41:55]

Done.

+    if (!PrintWindow(window_handle, mem_hdc.Get(), 0)) {
+      NOTREACHED();
+    }
+  } else {
+    BitBlt(mem_hdc.Get(),
+           0, 0, snapshot_bounds.width(), snapshot_bounds.height(),
+           window_hdc,
+           snapshot_bounds.x(), snapshot_bounds.y(),
+           SRCCOPY);
+  }
 
   // We now have a copy of the window contents in a DIB, so
   // encode it into a useful format for posting to the bug report
   // server.
   gfx::PNGCodec::Encode(bit_ptr, gfx::PNGCodec::FORMAT_BGRA,
                         snapshot_bounds.size(),
                         snapshot_bounds.width() * 4, true,
                         std::vector<gfx::PNGCodec::Comment>(),
                         png_representation);
 
   ReleaseDC(window_handle, window_hdc);
 
   return true;
 }
 
 }  // namespace browser