Cache a screen compatible DC to avoid re-creating it excessively.

ui/gfx/render_text_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 "ui/gfx/render_text_win.h"
 
 #include <algorithm>
 
 #include "base/i18n/break_iterator.h"
 #include "base/logging.h"
 #include "base/stl_util.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
-#include "base/win/scoped_hdc.h"
+#include "ui/gfx/screen_compatible_dc_win.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/canvas_skia.h"
 #include "ui/gfx/platform_font.h"
 
 namespace {
 
 // The maximum supported number of Uniscribe runs; a SCRIPT_ITEM is 8 bytes.
 // TODO(msw): Review memory use/failure? Max string length? Alternate approach?
 const int kGuessItems = 100;
 const int kMaxItems = 10000;
@@ skipping 563 matching lines @@
       script_item++;
     if (script_item_end >= style_range_end)
       style++;
     run->range.set_end(run_break);
     runs_.push_back(run);
   }
 }
 
 void RenderTextWin::LayoutVisualText() {
   HRESULT hr = E_FAIL;
-  base::win::ScopedCreateDC hdc(CreateCompatibleDC(NULL));
+  ScopedTemporaryScreenCompatibleDC hdc;
   std::vector<internal::TextRun*>::const_iterator run_iter;
   for (run_iter = runs_.begin(); run_iter < runs_.end(); ++run_iter) {
     internal::TextRun* run = *run_iter;
     size_t run_length = run->range.length();
     const wchar_t* run_text = &(text()[run->range.start()]);
     bool tried_fallback = false;
 
     // Select the font desired for glyph generation.
     SelectObject(hdc, run->font.GetNativeFont());
 
@@ skipping 125 matching lines @@
     internal::TextRun* run) {
   size_t caret = IndexOfAdjacentGrapheme(run->range.end(), CURSOR_BACKWARD);
   return SelectionModel(caret, caret, SelectionModel::LEADING);
 }
 
 RenderText* RenderText::CreateRenderText() {
   return new RenderTextWin;
 }
 
 }  // namespace gfx