Make ScopedGetDC() CHECK fail if GetDC(NULL) returns NULL.

chrome/browser/ui/views/omnibox/omnibox_view_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/views/omnibox/omnibox_view_win.h"
 
 #include <algorithm>
 #include <locale>
 #include <string>
 
 #include <richedit.h>
 #include <textserv.h>
 
 #include "base/auto_reset.h"
 #include "base/basictypes.h"
 #include "base/i18n/rtl.h"
 #include "base/lazy_instance.h"
 #include "base/memory/ref_counted.h"
 #include "base/property_bag.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "base/win/iat_patch_function.h"
+#include "base/win/scoped_hdc.h"
+#include "base/win/scoped_select_object.h"
 #include "base/win/windows_version.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/autocomplete/autocomplete_match.h"
 #include "chrome/browser/autocomplete/autocomplete_popup_model.h"
 #include "chrome/browser/autocomplete/keyword_provider.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/command_updater.h"
 #include "chrome/browser/net/url_fixer_upper.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
@@ skipping 452 matching lines @@
     if (keyboard_ != NULL)
       keyboard_->put_AttachedEditWindow(m_hWnd);
   }
 
   // NOTE: Do not use SetWordBreakProcEx() here, that is no longer supported as
   // of Rich Edit 2.0 onward.
   SendMessage(m_hWnd, EM_SETWORDBREAKPROC, 0,
               reinterpret_cast<LPARAM>(&WordBreakProc));
 
   // Get the metrics for the font.
-  HDC hdc = ::GetDC(NULL);
-  HGDIOBJ old_font = SelectObject(hdc, font_.GetNativeFont());
+  base::win::ScopedGetDC screen_dc(NULL);
+  base::win::ScopedSelectObject(screen_dc, font_.GetNativeFont());
   TEXTMETRIC tm = {0};
-  GetTextMetrics(hdc, &tm);
+  GetTextMetrics(screen_dc, &tm);
   int cap_height = font_.GetBaseline() - tm.tmInternalLeading;
   // The ratio of a font's x-height to its cap height.  Sadly, Windows
   // doesn't provide a true value for a font's x-height in its text
   // metrics, so we approximate.
   const float kXHeightRatio = 0.7f;
   font_x_height_ = static_cast<int>(
       (static_cast<float>(cap_height) * kXHeightRatio) + 0.5);
 
   // We set font_y_adjustment_ so that the ascender of the font gets
   // centered on the available height of the view.
   font_y_adjustment_ =
       (parent_view->GetInternalHeight(true) - cap_height) / 2 -
       tm.tmInternalLeading;
 
   // Get the number of twips per pixel, which we need below to offset our text
   // by the desired number of pixels.
-  const long kTwipsPerPixel = kTwipsPerInch / GetDeviceCaps(hdc, LOGPIXELSY);
-  // It's unsafe to delete a DC with a non-stock object selected, so restore the
-  // original font.
-  SelectObject(hdc, old_font);
-  ::ReleaseDC(NULL, hdc);
+  const long kTwipsPerPixel =
+      kTwipsPerInch / GetDeviceCaps(screen_dc, LOGPIXELSY);
 
   // Set the default character style -- adjust to our desired baseline.
   CHARFORMAT cf = {0};
   cf.dwMask = CFM_OFFSET;
   cf.yOffset = -font_y_adjustment_ * kTwipsPerPixel;
   SetDefaultCharFormat(cf);
 
   SetBackgroundColor(background_color_);
 
   // By default RichEdit has a drop target. Revoke it so that we can install our
@@ skipping 2174 matching lines @@
     bool popup_window_mode,
     LocationBarView* location_bar) {
   return new OmniboxViewWin(controller,
                             toolbar_model,
                             location_bar,
                             command_updater,
                             popup_window_mode,
                             location_bar);
 }
 #endif