Updating documentation

ppapi/c/pp_size.h

Index: ppapi/c/pp_size.h
===================================================================
--- ppapi/c/pp_size.h	(revision 73626)
+++ ppapi/c/pp_size.h	(working copy)
@@ -7,7 +7,7 @@
 
 /**
  * @file
- * Defines the API ...
+ * This file defines the width and height of a 2 dimenstional rectangle.
  */
 
 #include "ppapi/c/pp_macros.h"
@@ -17,8 +17,14 @@
  * @addtogroup Structs
  * @{
  */
+
+/**
+ * The PP_Size struct contains the size of a 2D rectangle.
+ */
 struct PP_Size {
+  /** This value represents the width of the rectangle. */
   int32_t width;
+  /** This value represents the height of the rectangle. */
   int32_t height;
 };
 PP_COMPILE_ASSERT_STRUCT_SIZE_IN_BYTES(PP_Size, 8);
@@ -30,6 +36,13 @@
  * @addtogroup Functions
  * @{
  */
+
+/**
+ * PP_MakeSize() creates a PP_Size given a width and height as int32_t values.
+ * @param[in] w An int32_t value representing a width.
+ * @param[in] h An int32_t value representing a height.
+ * @return A PP_Size structure.
+ */
 PP_INLINE struct PP_Size PP_MakeSize(int32_t w, int32_t h) {
   struct PP_Size ret;
   ret.width = w;