Support getting the font list in Pepper. This currently only works out of

ppapi/c/dev/ppb_font_dev.h

 /* Copyright (c) 2010 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 PPAPI_C_DEV_PPB_FONT_DEV_H_
 #define PPAPI_C_DEV_PPB_FONT_DEV_H_
 
 #include "ppapi/c/pp_bool.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_macros.h"
 #include "ppapi/c/pp_resource.h"
 #include "ppapi/c/pp_stdint.h"
 #include "ppapi/c/pp_var.h"
 
-#define PPB_FONT_DEV_INTERFACE_0_5 "PPB_Font(Dev);0.5"
-#define PPB_FONT_DEV_INTERFACE PPB_FONT_DEV_INTERFACE_0_5
+#define PPB_FONT_DEV_INTERFACE_0_6 "PPB_Font(Dev);0.6"
+#define PPB_FONT_DEV_INTERFACE PPB_FONT_DEV_INTERFACE_0_6
 
 struct PP_Point;
 struct PP_Rect;
 
 typedef enum {
-  // Uses the user's default web page font (normally either the default serif
-  // or sans serif font).
+  /**
+   * Uses the user's default web page font (normally either the default serif
+   * or sans serif font).
+   */
   PP_FONTFAMILY_DEFAULT = 0,
 
-  // These families will use the default web page font corresponding to the
-  // given family.
+  /**
+   * These families will use the default web page font corresponding to the
+   * given family.
+   */
   PP_FONTFAMILY_SERIF = 1,
   PP_FONTFAMILY_SANSSERIF = 2,
   PP_FONTFAMILY_MONOSPACE = 3
 } PP_FontFamily_Dev;
 PP_COMPILE_ASSERT_SIZE_IN_BYTES(PP_FontFamily_Dev, 4);
 
+/**
+ * Specifies the font weight. Normally users will only use NORMAL or BOLD.
+ */
 typedef enum {
   PP_FONTWEIGHT_100 = 0,
   PP_FONTWEIGHT_200,
   PP_FONTWEIGHT_300,
   PP_FONTWEIGHT_400,
   PP_FONTWEIGHT_500,
   PP_FONTWEIGHT_600,
   PP_FONTWEIGHT_700,
   PP_FONTWEIGHT_800,
   PP_FONTWEIGHT_900,
   PP_FONTWEIGHT_NORMAL = PP_FONTWEIGHT_400,
   PP_FONTWEIGHT_BOLD = PP_FONTWEIGHT_700
 } PP_FontWeight_Dev;
 PP_COMPILE_ASSERT_SIZE_IN_BYTES(PP_FontWeight_Dev, 4);
 
 struct PP_FontDescription_Dev {
-  // Font face name as a string. This can also be a Null var, in which case the
-  // generic family will be obeyed.
+  /**
+   * Font face name as a string. This can also be an undefined var, in which
+   * case the generic family will be obeyed.
+   */
   struct PP_Var face;
 
-  // When face is a Null string, this specifies the generic font family type
-  // to use. If the face is specified, this will be ignored.
+  /**
+   * When face is an undefined var, this specifies the generic font family type
+   * to use. If the face is specified, this will be ignored.
+   */
   PP_FontFamily_Dev family;
 
+  /**
+   * Size in pixels.
+   */
   uint32_t size;
 
-  // Normally you will use either PP_FONTWEIGHT_NORMAL or PP_FONTWEIGHT_BOLD.
+  /**
+   * Normally you will use either PP_FONTWEIGHT_NORMAL or PP_FONTWEIGHT_BOLD.
+   */
   PP_FontWeight_Dev weight;
 
   PP_Bool italic;
   PP_Bool small_caps;
 
-  // Adjustment to apply to letter and word spacing, respectively. Initialize
-  // to 0 to get normal spacing. Negative values bring letters/words closer
-  // together, positive values separate them.
+  /**
+   * Adjustment to apply to letter and word spacing, respectively. Initialize
+   * to 0 to get normal spacing. Negative values bring letters/words closer
+   * together, positive values separate them.
+   */
   int32_t letter_spacing;
   int32_t word_spacing;
 
-  // Ensure that this struct is 48-bytes wide by padding the end.  In some
-  // compilers, PP_Var is 8-byte aligned, so those compilers align this struct
-  // on 8-byte boundaries as well and pad it to 16 bytes even without this
-  // padding attribute.  This padding makes its size consistent across
-  // compilers.
+  /**
+   * Ensure that this struct is 48-bytes wide by padding the end.  In some
+   * compilers, PP_Var is 8-byte aligned, so those compilers align this struct
+   * on 8-byte boundaries as well and pad it to 16 bytes even without this
+   * padding attribute.  This padding makes its size consistent across
+   * compilers.
+   */
   int32_t padding;
 };
 PP_COMPILE_ASSERT_STRUCT_SIZE_IN_BYTES(PP_FontDescription_Dev, 48);
 
 struct PP_FontMetrics_Dev {
   int32_t height;
   int32_t ascent;
   int32_t descent;
   int32_t line_spacing;
   int32_t x_height;
 };
 PP_COMPILE_ASSERT_STRUCT_SIZE_IN_BYTES(PP_FontMetrics_Dev, 20);
 
 struct PP_TextRun_Dev {
-  // This var must either be a string or a null var (which will be treated as
-  // a 0-length string).
+  /**
+   * This var must either be a string or a null/undefined var (which will be
+   * treated as a 0-length string).
+   */
   struct PP_Var text;
 
-  // Set to PP_TRUE if the text is right-to-left.
+  /**
+   * Set to PP_TRUE if the text is right-to-left.
+   */
   PP_Bool rtl;
 
-  // Set to PP_TRUE to force the directionality of the text regardless of
-  // content
+  /**
+   * Set to PP_TRUE to force the directionality of the text regardless of
+   * content
+   */
   PP_Bool override_direction;
 };
 PP_COMPILE_ASSERT_STRUCT_SIZE_IN_BYTES(PP_TextRun_Dev, 24);
 
 struct PPB_Font_Dev {
-  // Returns a font which best matches the given description. The return value
-  // will have a non-zero ID on success, or zero on failure.
+  /**
+   * Returns a list of all available font families on the system. You can use
+   * this list to decide whether to Create() a font.
+   *
+   * The return value will be a single string with null characters delimiting
+   * the end of each font name. For example: "Arial\0Courier\0Times\0".
+   *
+   * Returns an undefined var on failure (this typically means you passed an
+   * invalid instance).
+   */
+  struct PP_Var (*GetFontFamilies)(PP_Instance instance);
+
+  /**
+   * Returns a font which best matches the given description. The return value
+   * will have a non-zero ID on success, or zero on failure.
+   */
   PP_Resource (*Create)(PP_Instance instance,
                         const struct PP_FontDescription_Dev* description);
 
-  // Returns PP_TRUE if the given resource is a Font. Returns PP_FALSE if the
-  // resource is invalid or some type other than a Font.
+  /**
+   * Returns PP_TRUE if the given resource is a Font. Returns PP_FALSE if the
+   * resource is invalid or some type other than a Font.
+   */
   PP_Bool (*IsFont)(PP_Resource resource);
 
-  // Loads the description and metrics of the font into the given structures.
-  // The description will be different than the description the font was
-  // created with since it will be filled with the real values from the font
-  // that was actually selected.
-  //
-  // The PP_Var in the description should be of type Void on input. On output,
-  // this will contain the string and will have a reference count of 1. The
-  // plugin is responsible for calling Release on this var.
-  //
-  // Returns PP_TRUE on success, PP_FALSE if the font is invalid or if the Var
-  // in the description isn't Null (to prevent leaks).
+  /**
+   * Loads the description and metrics of the font into the given structures.
+   * The description will be different than the description the font was
+   * created with since it will be filled with the real values from the font
+   * that was actually selected.
+   *
+   * The PP_Var in the description should be of type Void on input. On output,
+   * this will contain the string and will have a reference count of 1. The
+   * plugin is responsible for calling Release on this var.
+   *
+   * Returns PP_TRUE on success, PP_FALSE if the font is invalid or if the Var
+   * in the description isn't Null (to prevent leaks).
+   */
   PP_Bool (*Describe)(PP_Resource font,
                       struct PP_FontDescription_Dev* description,
                       struct PP_FontMetrics_Dev* metrics);
 
-  // Draws the text to the image buffer.
-  //
-  // The given point represents the baseline of the left edge of the font,
-  // regardless of whether it is left-to-right or right-to-left (in the case of
-  // RTL text, this will actually represent the logical end of the text).
-  //
-  // The clip is optional and may be NULL. In this case, the text will be
-  // clipped to the image.
-  //
-  // The image_data_is_opaque flag indicates whether subpixel antialiasing can
-  // be performend, if it is supported. When the image below the text is
-  // opaque, subpixel antialiasing is supported and you should set this to
-  // PP_TRUE to pick up the user's default preferences. If your plugin is
-  // partially transparent, then subpixel antialiasing is not possible and
-  // grayscale antialiasing will be used instead (assuming the user has
-  // antialiasing enabled at all).
+  /**
+   * Draws the text to the image buffer.
+   *
+   * The given point represents the baseline of the left edge of the font,
+   * regardless of whether it is left-to-right or right-to-left (in the case of
+   * RTL text, this will actually represent the logical end of the text).
+   *
+   * The clip is optional and may be NULL. In this case, the text will be
+   * clipped to the image.
+   *
+   * The image_data_is_opaque flag indicates whether subpixel antialiasing can
+   * be performend, if it is supported. When the image below the text is
+   * opaque, subpixel antialiasing is supported and you should set this to
+   * PP_TRUE to pick up the user's default preferences. If your plugin is
+   * partially transparent, then subpixel antialiasing is not possible and
+   * grayscale antialiasing will be used instead (assuming the user has
+   * antialiasing enabled at all).
+   */
   PP_Bool (*DrawTextAt)(PP_Resource font,
                         PP_Resource image_data,
                         const struct PP_TextRun_Dev* text,
                         const struct PP_Point* position,
                         uint32_t color,
                         const struct PP_Rect* clip,
                         PP_Bool image_data_is_opaque);
 
-  // Returns the width of the given string. If the font is invalid or the var
-  // isn't a valid string, this will return -1.
-  //
-  // Note that this function handles complex scripts such as Arabic, combining
-  // accents, etc. so that adding the width of substrings won't necessarily
-  // produce the correct width of the entire string.
-  //
-  // Returns -1 on failure.
+  /**
+   * Returns the width of the given string. If the font is invalid or the var
+   * isn't a valid string, this will return -1.
+   *
+   * Note that this function handles complex scripts such as Arabic, combining
+   * accents, etc. so that adding the width of substrings won't necessarily
+   * produce the correct width of the entire string.
+   *
+   * Returns -1 on failure.
+   */
   int32_t (*MeasureText)(PP_Resource font,
                          const struct PP_TextRun_Dev* 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.
+  /**
+   * 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.
+   */
   uint32_t (*CharacterOffsetForPixel)(PP_Resource font,
                                       const struct PP_TextRun_Dev* 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.
+  /**
+   * 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_TextRun_Dev* text,
                                      uint32_t char_offset);
+
+
 };
 
 #endif  /* PPAPI_C_DEV_PPB_FONT_DEV_H_ */