Add plumbing in blink to allow overriding the skia font manager.

content/child/font_warmup_win.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 "content/child/font_warmup_win.h"
 
 #include <dwrite.h>
 #include <stdint.h>
 #include <map>
 
@@ skipping 112 matching lines @@
     DWORD get_proc_address_get_last_error = GetLastError();
     base::debug::Alias(&dwrite_create_factory_proc);
     base::debug::Alias(&get_proc_address_get_last_error);
     CHECK(false);
   }
   CHECK(SUCCEEDED(dwrite_create_factory_proc(
       DWRITE_FACTORY_TYPE_ISOLATED, __uuidof(IDWriteFactory),
       reinterpret_cast<IUnknown**>(factory))));
 }
 
-HRESULT STDMETHODCALLTYPE StubFontCollection(IDWriteFactory* factory,
-                                             IDWriteFontCollection** col,
-                                             BOOL checkUpdates) {
-  // We always return pre-created font collection from here.
-  IDWriteFontCollection* custom_collection = GetCustomFontCollection(factory);
-  DCHECK(custom_collection != nullptr);
-  *col = custom_collection;
-  return S_OK;
-}
-
-void PatchDWriteFactory(IDWriteFactory* factory) {
-  const unsigned int kGetSystemFontCollectionVTableIndex = 3;
-
-  PROC* vtable = *reinterpret_cast<PROC**>(factory);
-  PROC* function_ptr = &vtable[kGetSystemFontCollectionVTableIndex];
-  void* stub_function = &StubFontCollection;
-  base::win::ModifyCode(function_ptr, &stub_function, sizeof(PROC));
-}
-
 // Class to fake out a DC or a Font object. Maintains a reference to a
 // SkTypeFace to emulate the simple operation of a DC and Font.
 class FakeGdiObject : public base::RefCountedThreadSafe<FakeGdiObject> {
  public:
   FakeGdiObject(uint32_t magic, void* handle)
       : handle_(handle), magic_(magic) {}
 
   void set_typeface(const skia::RefPtr<SkTypeface>& typeface) {
     typeface_ = typeface;
   }
@@ skipping 309 matching lines @@
   paint_warmup.setTypeface(typeface);
   wchar_t glyph = L'S';
   paint_warmup.measureText(&glyph, 2);
 }
 
 SkFontMgr* GetPreSandboxWarmupFontMgr() {
   if (!g_warmup_fontmgr) {
     IDWriteFactory* factory;
     CreateDirectWriteFactory(&factory);
 
-    GetCustomFontCollection(factory);
-
-    PatchDWriteFactory(factory);
-
-    blink::WebFontRendering::setDirectWriteFactory(factory);
-    g_warmup_fontmgr = SkFontMgr_New_DirectWrite(factory);
+    g_warmup_fontmgr =
+        SkFontMgr_New_DirectWrite(factory, GetCustomFontCollection(factory));
+    blink::WebFontRendering::setSkiaFontManager(g_warmup_fontmgr);
   }
   return g_warmup_fontmgr;
 }
 
 GdiFontPatchData* PatchGdiFontEnumeration(const base::FilePath& path) {
   if (ShouldUseDirectWriteFontProxyFieldTrial() && !g_warmup_fontmgr)
     g_warmup_fontmgr = SkFontMgr_New_DirectWrite();
   // If not using the font proxy, we assume |g_warmup_fontmgr| is already
   // initialized before this function is called.
   DCHECK(g_warmup_fontmgr);
@@ skipping 23 matching lines @@
   // down for the CC HUD code, so use the same one here. Note that we don't use
   // a monospace as would be nice in an attempt to avoid a small startup time
   // regression, see http://crbug.com/463613.
   skia::RefPtr<SkTypeface> hud_typeface = skia::AdoptRef(
       GetPreSandboxWarmupFontMgr()->legacyCreateTypeface("Times New Roman", 0));
   DoPreSandboxWarmupForTypeface(hud_typeface.get());
   gfx::SetHudTypeface(hud_typeface);
 }
 
 }  // namespace content