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

ui/gfx/render_text_win.cc

Index: ui/gfx/render_text_win.cc
===================================================================
--- ui/gfx/render_text_win.cc	(revision 120360)
+++ ui/gfx/render_text_win.cc	(working copy)
@@ -11,7 +11,7 @@
 #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"
@@ -595,7 +595,7 @@
 
 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;