A second attempt at forcing 8-byte alignment of the time stamp....

ppapi/c/pp_input_event.h

Index: ppapi/c/pp_input_event.h
===================================================================
--- ppapi/c/pp_input_event.h	(revision 66151)
+++ ppapi/c/pp_input_event.h	(working copy)
@@ -150,14 +150,15 @@
   PP_Bool scroll_by_page;
 };
 
-/* Ensure the elements of the struct (especially the time_stamp) are aligned on
-   8-byte boundaries, since some compilers align doubles on 8-byte boundaries
-   for 32-bit x86, and some align on 4-byte boundaries. */
-#pragma pack(push, 8)
 struct PP_InputEvent {
   /** Identifies the type of the event. */
   PP_InputEvent_Type type;
 
+  /* Ensure the time_stamp is aligned on an 8-byte boundary relative to the
+     start of the struct. Some compilers align doubles on 8-byte boundaries
+     for 32-bit x86, and some align on 4-byte boundaries. */
+  int32_t padding;
+
   /**
    * When this event was generated. This is not relative to any particular
    * epoch, the most you can do is compare time stamps.
@@ -178,10 +179,7 @@
     char padding[64];
   } u;
 };
-#pragma pack(pop)
-/* TODO(dmichael):  Figure out why the input event is not 80 bytes wide on Mac.
 PP_COMPILE_ASSERT_STRUCT_SIZE_IN_BYTES(PP_InputEvent, 80);
- */
 
 /**
  * @}