Implement right-to-left text rendering in Pepper.

ppapi/c/trusted/ppb_browser_font_trusted.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.
  */
 
 /* From trusted/ppb_browser_font_trusted.idl,
- *   modified Tue Feb 14 08:45:20 2012.
+ *   modified Wed Jun 27 14:43:20 2012.
  */
 
 #ifndef PPAPI_C_TRUSTED_PPB_BROWSER_FONT_TRUSTED_H_
 #define PPAPI_C_TRUSTED_PPB_BROWSER_FONT_TRUSTED_H_
 
 #include "ppapi/c/pp_bool.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_macros.h"
 #include "ppapi/c/pp_point.h"
 #include "ppapi/c/pp_rect.h"
@@ skipping 227 matching lines @@
    *
    * Returns -1 on failure.
    */
   int32_t (*MeasureText)(PP_Resource font,
                          const struct PP_BrowserFont_Trusted_TextRun* text);
   /**
    * Returns the character at the given pixel X position from the beginning of
    * the string. This handles complex scripts such as Arabic, where characters
    * may be combined or replaced depending on the context. Returns (uint32)-1
    * on failure.
+   *
+   * TODO(brettw) this function may be broken. See the CharPosRTL test. It
+   * seems to tell you "insertion point" rather than painting position. This
+   * is useful but maybe not what we intended here.
    */
   uint32_t (*CharacterOffsetForPixel)(
       PP_Resource font,
       const struct PP_BrowserFont_Trusted_TextRun* text,
       int32_t pixel_position);
   /**
    * Returns the horizontal advance to the given character if the string was
    * placed at the given position. This handles complex scripts such as Arabic,
    * where characters may be combined or replaced depending on context. Returns
    * -1 on error.
    */
   int32_t (*PixelOffsetForCharacter)(
       PP_Resource font,
       const struct PP_BrowserFont_Trusted_TextRun* text,
       uint32_t char_offset);
 };
 
 typedef struct PPB_BrowserFont_Trusted_1_0 PPB_BrowserFont_Trusted;
 /**
  * @}
  */
 
 #endif  /* PPAPI_C_TRUSTED_PPB_BROWSER_FONT_TRUSTED_H_ */