Mac: OOP font loading should run on FILE thread.

content/common/mac/font_loader.h

 // Copyright (c) 2012 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.
 
 #ifndef CONTENT_COMMON_MAC_FONT_LOADER_H_
 #define CONTENT_COMMON_MAC_FONT_LOADER_H_
 #pragma once
 
 #include <ApplicationServices/ApplicationServices.h>
 
 #include "base/shared_memory.h"
 #include "content/common/content_export.h"
 
 #ifdef __OBJC__
 @class NSFont;
 #else
 class NSFont;
 #endif
 
+struct FontDescriptor;
+
 // Provides functionality to transmit fonts over IPC.
 //
 // Note about font formats: .dfont (datafork suitcase) fonts are currently not
 // supported by this code since CGFontCreateWithDataProvider() can't handle them
 // directly.
 
 class FontLoader {
  public:
-  // Load a font specified by |font_to_encode| into a shared memory buffer
-  // suitable for sending over IPC.
+  struct Result {

[jeremy, 2012/04/04 08:35:38]

can you add a comment here describing what the structure is used for and why
it's needed.

[bashi, 2012/04/04 09:36:22]

Done.

+    uint32 font_data_size;
+    base::SharedMemory font_data;
+    uint32 font_id;
+  };
+  // Load a font specified by |font| into a shared memory buffer suitable for
+  // sending over IPC.
   //
   // On return:
-  //  returns true on success, false on failure.
-  //  |font_data| - shared memory buffer containing the raw data for the font
-  // file.
-  //  |font_data_size| - size of data contained in |font_data|.
-  //  |font_id| - unique identifier for the on-disk file we load for the font.
+  //  |result->font_data| - shared memory buffer containing the raw data for
+  // the font file.

[jeremy, 2012/04/04 08:35:38]

Can you add a comment as to what to expect in this field on failure?

[bashi, 2012/04/04 09:36:22]

The buffer won't be valid on failure. Added description.

+  //  |result->font_data_size| - size of data contained in |result->font_data|.
+  // This value is zero on failure.
+  //  |result->font_id| - unique identifier for the on-disk file we load for
+  // the font. This value is zero on failure.
   CONTENT_EXPORT
-  static bool LoadFontIntoBuffer(NSFont* font_to_encode,
-                                 base::SharedMemory* font_data,
-                                 uint32* font_data_size,
-                                 uint32* font_id);
+  static void LoadFont(const FontDescriptor& font, FontLoader::Result* result);
 
   // Given a shared memory buffer containing the raw data for a font file, load
   // the font and return a CGFontRef.
   //
   // |data| - A shared memory handle pointing to the raw data from a font file.
   // |data_size| - Size of |data|.
   //
   // On return:
   //  returns true on success, false on failure.
   //  |out| - A CGFontRef corresponding to the designated font.
   //  The caller is responsible for releasing this value via CGFontRelease()
   //  when done.
   CONTENT_EXPORT
   static bool CGFontRefFromBuffer(base::SharedMemoryHandle font_data,
                                   uint32 font_data_size,
                                   CGFontRef* out);
 };
 
 #endif // CONTENT_COMMON_MAC_FONT_LOADER_H_