Support GrabWindowSnapshot with no g_browser_process

chrome/browser/ui/window_snapshot/window_snapshot_win.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 "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"
-#include "ui/gfx/gdi_util.h"
-#include "ui/gfx/rect.h"
-#include "ui/gfx/size.h"
-
-namespace {
-
-gfx::Rect GetWindowBounds(gfx::NativeWindow window_handle) {
-  RECT content_rect = {0, 0, 0, 0};
-  if (window_handle) {
-    ::GetWindowRect(window_handle, &content_rect);
-  } else {
-    MONITORINFO monitor_info = {};
-    monitor_info.cbSize = sizeof(monitor_info);
-    if (GetMonitorInfo(MonitorFromWindow(NULL, MONITOR_DEFAULTTOPRIMARY),
-                       &monitor_info)) {
-      content_rect = monitor_info.rcMonitor;
-    }
-  }
-  content_rect.right++;  // Match what PrintWindow wants.
-
-  return gfx::Rect(content_rect.right - content_rect.left,
-                   content_rect.bottom - content_rect.top);
-}
-
-}  // namespace
-
-namespace chrome {
-
-bool GrabWindowSnapshotImpl(gfx::NativeWindow window_handle,
-                            std::vector<unsigned char>* png_representation,
-                            const gfx::Rect& snapshot_bounds) {
-  DCHECK(snapshot_bounds.right() <= GetWindowBounds(window_handle).right());
-  DCHECK(snapshot_bounds.bottom() <= GetWindowBounds(window_handle).bottom());
-
-  // 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,
-                       reinterpret_cast<BITMAPINFO*>(&hdr),
-                       DIB_RGB_COLORS,
-                       reinterpret_cast<void **>(&bit_ptr),
-                       NULL, 0));
-
-  base::win::ScopedSelectObject select_bitmap(mem_hdc, 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(),
-         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 =
-      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).  Always BitBlt when grabbing the whole screen.
-  if (snapshot_bounds.origin() == gfx::Point() && print_window && window_handle)
-    (*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);
-
-  // 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 chrome