Implement direct write fallback proxy

content/child/dwrite_font_proxy/dwrite_font_proxy_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_win.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <utility>
@@ skipping 223 matching lines @@
   uint32_t index = family_index;
   // CreateCustomFontCollection ends up calling
   // DWriteFontCollectionProxy::CreateEnumeratorFromKey.
   HRESULT hr = factory_->CreateCustomFontCollection(
       this /*collectionLoader*/, reinterpret_cast<const void*>(&index),
       sizeof(index), containing_collection);
 
   return SUCCEEDED(hr);
 }
 
+bool DWriteFontCollectionProxy::GetFontFamily(UINT32 family_index,
+                                              const base::string16& family_name,
+                                              IDWriteFontFamily** font_family) {
+  if (!CreateFamily(family_index))

[ananta, 2016/04/12 23:44:39]

Please check for valid parameters here, especially the out ones. 

[Ilya Kulshin, 2016/04/13 01:33:28]

Added a dcheck that font_family is not null and family_name is not empty.
CreateFamily validates family_index.

+    return false;
+
+  mswr::ComPtr<DWriteFontFamilyProxy>& family = families_[family_index];
+  if (!family->IsLoaded() || family->GetName().empty())
+    family->SetName(family_name);
+
+  family.CopyTo(font_family);
+  return true;
+}
+
 bool DWriteFontCollectionProxy::LoadFamilyNames(
     UINT32 family_index,
     IDWriteLocalizedStrings** localized_strings) {
   TRACE_EVENT0("dwrite", "FontProxy::LoadFamilyNames");
 
   std::vector<std::pair<base::string16, base::string16>> strings;
   if (!GetSender()->Send(
           new DWriteFontProxyMsg_GetFamilyNames(family_index, &strings))) {
     return false;
   }
@@ skipping 276 matching lines @@
 
 HRESULT FontFileStream::RuntimeClassInitialize(
     const base::string16& file_name) {
   data_.Initialize(base::FilePath(file_name));
   if (!data_.IsValid())
     return E_FAIL;
   return S_OK;
 }
 
 }  // namespace content