Added restricted font fallback to custom font collection loader.

content/renderer/renderer_font_platform_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/renderer/renderer_font_platform_win.h"
 
 #include <dwrite.h>
 #include <string>
 #include <vector>
 #include <wrl/implements.h>
@@ skipping 31 matching lines @@
                               UINT32 key_size,
                               IDWriteFontFileEnumerator** file_enumerator);
 
   static HRESULT Initialize(IDWriteFactory* factory);
 
   UINT32 GetFontMapSize();
 
   std::wstring GetFontNameFromKey(UINT32 idx);
 
   bool LoadFontListFromRegistry();
+  bool LoadRestrictedFontList();
 
   FontCollectionLoader() {};
   virtual ~FontCollectionLoader() {};
 
  private:
   mswr::ComPtr<IDWriteFontFileLoader> file_loader_;
 
   std::vector<std::wstring> reg_fonts_;
 };
 
@@ skipping 214 matching lines @@
       std::vector<base::FilePath::StringType> components;
       path.GetComponents(&components);
       if (components.size() == 1) {
         reg_fonts_.push_back(value.c_str());
       }
     }
   }
   return true;
 }
 
+// This list is mainly based on prefs/prefs_tab_helper.cc kFontDefaults.
+const wchar_t* kRestrictedFontSet[] = {
+  L"times.ttf",
+  L"timesbd.ttf",
+  L"timesbi.ttf",
+  L"timesi.ttf",
+  L"cour.ttf",
+  L"courbd.ttf",
+  L"courbi.ttf",
+  L"couri.ttf",
+  L"consola.ttf",
+  L"consolab.ttf",
+  L"consolai.ttf",
+  L"consolaz.ttf",
+  L"arial.ttf",
+  L"arialbd.ttf",
+  L"arialbi.ttf",
+  L"ariali.ttf",
+  L"comic.ttf",
+  L"comicbd.ttf",
+  L"comici.ttf",
+  L"comicz.ttf",
+  L"impact.ttf",
+  L"segoeui.ttf",
+  L"segoeuib.ttf",
+  L"segoeuii.ttf",
+  L"msgothic.ttc",
+  L"msmincho.ttc",
+  L"gulim.ttc",
+  L"batang.ttc",
+  L"simsun.ttc",
+  L"mingliu.ttc",

[cpu_(ooo_6.6-7.5), 2014/08/29 01:14:31]

1) add a comment for each font that indicates which IDS_ this comes from, for
example cursive or monospace, etc.

2) please check if this is inclusive for win7.

[Shrikant Kelkar, 2014/08/29 01:41:28]

Done.

+};
+
+bool FontCollectionLoader::LoadRestrictedFontList() {
+  reg_fonts_.clear();
+  reg_fonts_.assign(kRestrictedFontSet,
+                    kRestrictedFontSet + _countof(kRestrictedFontSet));
+  return true;
+}
+
 }  // namespace
 
 namespace content {
 
 mswr::ComPtr<IDWriteFontCollection> g_font_collection;
 
 IDWriteFontCollection* GetCustomFontCollection(IDWriteFactory* factory) {
   if (g_font_collection.Get() != NULL)
     return g_font_collection.Get();
 
   base::TimeTicks start_tick = base::TimeTicks::Now();
 
   FontCollectionLoader::Initialize(factory);
 
-  HRESULT hr = factory->CreateCustomFontCollection(
-      g_font_loader.Get(), NULL, 0, g_font_collection.GetAddressOf());
+  // We try here to put arbitrary limit on max number of fonts that could
+  // be loaded, otherwise we fallback to restricted set of fonts.
+  const UINT32 kMaxFontThreashold = 1000;

[cpu_(ooo_6.6-7.5), 2014/08/29 01:14:31]

misspell --> threshold

[Shrikant Kelkar, 2014/08/29 01:41:28]

Done.

+  HRESULT hr = E_FAIL;
+  if (g_font_loader->GetFontMapSize() < kMaxFontThreashold) {
+    hr = factory->CreateCustomFontCollection(
+        g_font_loader.Get(), NULL, 0, g_font_collection.GetAddressOf());
+  }
 

[cpu_(ooo_6.6-7.5), 2014/08/29 01:17:53]

I rather have an "else" than rely on hr being e_fail.

Do we need the 351-355 block still? if so then move it to the end and add an
debug::alias bool that records the fallback.

[Shrikant Kelkar, 2014/08/29 01:41:28]

Idea is to execute it in both cases, try registry first if fonts less than 1000
if that fails too, then load restricted set. If fonts more than 1000, directly
go for restricted set.
Done.

   base::TimeDelta time_delta = base::TimeTicks::Now() - start_tick;
   int64 delta = time_delta.ToInternalValue();
   base::debug::Alias(&delta);
   UINT32 size = g_font_loader->GetFontMapSize();
   base::debug::Alias(&size);
 
+  if (FAILED(hr) || !g_font_collection.Get()) {
+    // We will try here just one more time with restricted font set.
+    g_font_loader->LoadRestrictedFontList();
+    hr = factory->CreateCustomFontCollection(
+        g_font_loader.Get(), NULL, 0, g_font_collection.GetAddressOf());
+  }
+
   CHECK(SUCCEEDED(hr));
   CHECK(g_font_collection.Get() != NULL);
 
   base::debug::ClearCrashKey(kFontKeyName);
 
   return g_font_collection.Get();
 }
 
 }  // namespace content