Fix up some types in the API.

ppapi/c/ppb_core.h

Index: ppapi/c/ppb_core.h
diff --git a/ppapi/c/ppb_core.h b/ppapi/c/ppb_core.h
index 6571db008050769ccfe19a826563dd9515d77bde..59efc246a97b519eaf4e8b20895956889a272d59 100644
--- a/ppapi/c/ppb_core.h
+++ b/ppapi/c/ppb_core.h
@@ -13,7 +13,7 @@
 
 struct PP_CompletionCallback;
 
-#define PPB_CORE_INTERFACE "PPB_Core;0.3"
+#define PPB_CORE_INTERFACE "PPB_Core;0.4"
 
 /**
  * @file
@@ -54,11 +54,11 @@ struct PPB_Core {
   /**
    * MemAlloc is a pointer to a function that allocate memory.
    *
-   * @param[in] num_bytes A size_t number of bytes to allocate.
+   * @param[in] num_bytes A number of bytes to allocate.
    * @return A pointer to the memory if successful, NULL If the
    * allocation fails.
    */
-  void* (*MemAlloc)(size_t num_bytes);
+  void* (*MemAlloc)(uint32_t num_bytes);
 
   /**
    * MemFree is a pointer to a function that deallocates memory.