Use ChildThreadImpl::thread_safe_sender in font proxy if available

content/child/dwrite_font_proxy/dwrite_font_proxy_init_win.cc

 // Copyright 2015 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/dwrite_font_proxy/dwrite_font_proxy_init_win.h"
 
 #include <dwrite.h>
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/debug/alias.h"
 #include "base/win/iat_patch_function.h"
 #include "base/win/windows_version.h"
+#include "content/child/child_thread_impl.h"
 #include "content/child/dwrite_font_proxy/dwrite_font_proxy_win.h"
 #include "content/child/dwrite_font_proxy/font_fallback_win.h"
 #include "content/child/font_warmup_win.h"
+#include "content/child/thread_safe_sender.h"
 #include "skia/ext/fontmgr_default_win.h"
 #include "third_party/WebKit/public/web/win/WebFontRendering.h"
 #include "third_party/skia/include/ports/SkFontMgr.h"
 #include "third_party/skia/include/ports/SkTypeface_win.h"
 
 namespace mswr = Microsoft::WRL;
 
 namespace content {
 
 namespace {
@@ skipping 40 matching lines @@
 
   CreateDirectWriteFactory(&factory);
 
   if (!g_font_collection) {
     mswr::MakeAndInitialize<DWriteFontCollectionProxy>(
         &g_font_collection, factory.Get(), g_sender_override);
   }
 
   mswr::ComPtr<IDWriteFontFallback> font_fallback;
   mswr::ComPtr<IDWriteFactory2> factory2;
+  IPC::Sender* sender = g_sender_override;
+
+  // Hack for crbug.com/631254: set the sender if we can get one, so that when
+  // Flash calls into the font proxy from a different thread we will have a
+  // sender available.
+  if (!sender && ChildThreadImpl::current())
+    sender = ChildThreadImpl::current()->thread_safe_sender();
+
   if (SUCCEEDED(factory.As(&factory2)) && factory2.Get()) {
     mswr::MakeAndInitialize<FontFallback>(
-        &font_fallback, g_font_collection.Get(), g_sender_override);
+        &font_fallback, g_font_collection.Get(), sender);
   }
 
   sk_sp<SkFontMgr> skia_font_manager(SkFontMgr_New_DirectWrite(
       factory.Get(), g_font_collection.Get(), font_fallback.Get()));
   blink::WebFontRendering::setSkiaFontManager(skia_font_manager.get());
 
   // Add an extra ref for SetDefaultSkiaFactory, which keeps a ref but doesn't
   // addref.
   skia_font_manager->ref();
   SetDefaultSkiaFactory(skia_font_manager.get());
@@ skipping 14 matching lines @@
 void UninitializeDWriteFontProxy() {
   if (g_font_collection)
     g_font_collection->Unregister();
 }
 
 void SetDWriteFontProxySenderForTesting(IPC::Sender* sender) {
   g_sender_override = sender;
 }
 
 }  // namespace content