Make a new test to enforce the sizes of all structs and enums in the C API....

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_macros.h"
 #include "ppapi/c/pp_module.h"
 #include "ppapi/c/pp_resource.h"
 #include "ppapi/c/pp_stdint.h"
 #include "ppapi/c/pp_var.h"
 
-#define PPB_FONT_DEV_INTERFACE "PPB_Font(Dev);0.2"
+#define PPB_FONT_DEV_INTERFACE "PPB_Font(Dev);0.3"
 
 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).
   PP_FONTFAMILY_DEFAULT = 0,
 
   // 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);
 
 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.
   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.
   PP_FontFamily_Dev family;
 
   uint32_t size;
 
   // 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.
-  int letter_spacing;
-  int word_spacing;
+  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.
+  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).
   struct PP_Var text;
 
   // 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
   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.
   PP_Resource (*Create)(PP_Module module,
                         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.
   PP_Bool (*IsFont)(PP_Resource resource);
@@ skipping 55 matching lines @@
 
   // 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.
   int32_t (*PixelOffsetForCharacter)(PP_Resource font,
                                      const struct PP_TextRun_Dev* text,
                                      uint32_t char_offset);
 };
 
 #endif  // PPAPI_C_DEV_PPB_FONT_DEV_H_