Implementation of dwrite font proxy and removal of dwrite font cache

ui/gfx/win/direct_write.cc

 // Copyright 2014 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/win/direct_write.h"
 
 #include <dwrite.h>
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
 #include "base/win/registry.h"
 #include "base/win/scoped_comptr.h"
 #include "base/win/windows_version.h"
 #include "skia/ext/fontmgr_default_win.h"
 #include "third_party/skia/include/ports/SkTypeface_win.h"
 #include "ui/gfx/platform_font_win.h"
 #include "ui/gfx/switches.h"
 #include "ui/gfx/win/dpi.h"
 
 namespace gfx {
 namespace win {
 
+base::win::ScopedComPtr<IDWriteFactory> factory_;
+
 namespace {
 
 static bool dwrite_enabled = false;
 
 }
 
 bool ShouldUseDirectWrite() {
   // If the flag is currently on, and we're on Win7 or above, we enable
   // DirectWrite. Skia does not require the additions to DirectWrite in QFE
   // 2670838, but a simple 'better than XP' check is not enough.
@@ skipping 40 matching lines @@
   if (!dwrite_dll)
     return;
 
   DWriteCreateFactoryProc dwrite_create_factory_proc =
       reinterpret_cast<DWriteCreateFactoryProc>(
           GetProcAddress(dwrite_dll, "DWriteCreateFactory"));
   // Not finding the DWriteCreateFactory function indicates a corrupt dll.
   if (!dwrite_create_factory_proc)
     return;
 
-  base::win::ScopedComPtr<IDWriteFactory> factory;
-
   // Failure to create the DirectWrite factory indicates a corrupt dll.
   if (FAILED(dwrite_create_factory_proc(
-          DWRITE_FACTORY_TYPE_SHARED,
-        __uuidof(IDWriteFactory),
-        reinterpret_cast<IUnknown**>(factory.Receive()))))
+          DWRITE_FACTORY_TYPE_SHARED, __uuidof(IDWriteFactory),
+          reinterpret_cast<IUnknown**>(factory_.Receive()))))
     return;
 
   // The skia call to create a new DirectWrite font manager instance can fail
   // if we are unable to get the system font collection from the DirectWrite
   // factory. The GetSystemFontCollection method in the IDWriteFactory
   // interface fails with E_INVALIDARG on certain Windows 7 gold versions
   // (6.1.7600.*). We should just use GDI in these cases.
-  SkFontMgr* direct_write_font_mgr = SkFontMgr_New_DirectWrite(factory.get());
+  SkFontMgr* direct_write_font_mgr = SkFontMgr_New_DirectWrite(factory_.get());
   if (!direct_write_font_mgr)
     return;
   dwrite_enabled = true;
   SetDefaultSkiaFactory(direct_write_font_mgr);
-  gfx::PlatformFontWin::SetDirectWriteFactory(factory.get());
+  gfx::PlatformFontWin::SetDirectWriteFactory(factory_.get());
 }
 
 bool IsDirectWriteEnabled() {
   return dwrite_enabled;
 }
 
+void GetDWriteFactory(IDWriteFactory** factory) {
+  MaybeInitializeDirectWrite();
+  base::win::ScopedComPtr<IDWriteFactory> factory_ref = factory_;
+  *factory = factory_ref.Detach();
+}
+
 }  // namespace win
 }  // namespace gfx