New implementation of font precache on Windows.

content/common/child_process_host.h

Index: content/common/child_process_host.h
diff --git a/content/common/child_process_host.h b/content/common/child_process_host.h
index 20708c254ca7acb6f48a51a0dfd902695ced6b69..473b3443ab3e95b79f1256cdaaf93dbe2ee2556d 100644
--- a/content/common/child_process_host.h
+++ b/content/common/child_process_host.h
@@ -8,6 +8,7 @@
 
 #include <string>
 #include <vector>
+#include <map>
 
 #include "build/build_config.h"
 
@@ -17,6 +18,7 @@
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/singleton.h"
 #include "content/common/content_notification_types.h"
 #include "ipc/ipc_channel_proxy.h"
 
@@ -86,7 +88,8 @@ class ChildProcessHost : public IPC::Channel::Listener,
 #if defined(OS_WIN)
   // See comments in the cc file. This is a common hack needed for a process
   // hosting a sandboxed child process. Hence it lives in this file.
-  static void PreCacheFont(LOGFONT font);
+  static void PreCacheFont(LOGFONT font, int pid);
+  static void ReleaseCachedFonts(int pid);
 #endif  // defined(OS_WIN)
 
   // IPC::Message::Sender implementation.
@@ -148,6 +151,35 @@ class ChildProcessHost : public IPC::Channel::Listener,
 
   ListenerHook listener_;
 
+#if defined (OS_WIN)
+  class FontCache {
+   public:
+    static FontCache* GetInstance();
+    void PreCacheFont(LOGFONT font, int pid);
+    void ReleaseCachedFonts(int pid);
+
+   private:
+    struct CacheElement {
+      CacheElement();
+      ~CacheElement();
+
+      HFONT font_;
+      HDC dc_;
+      int ref_count_;
+    };
+    friend struct DefaultSingletonTraits<FontCache>;
+
+    FontCache();
+    ~FontCache();
+
+    std::map<std::wstring, CacheElement> cache_;
+    std::map<int, std::vector<std::wstring> > pid_font_map_;
+    base::Lock mutex_;
+
+    DISALLOW_COPY_AND_ASSIGN(FontCache);
+  };
+#endif
+
   bool opening_channel_;  // True while we're waiting the channel to be opened.
   scoped_ptr<IPC::Channel> channel_;
   std::string channel_id_;