[PPAPI] Documentation fixes.

ppapi/api/ppb_message_loop.idl

Index: ppapi/api/ppb_message_loop.idl
diff --git a/ppapi/api/ppb_message_loop.idl b/ppapi/api/ppb_message_loop.idl
index 5ae00b128a15e6f02a52af95604980b43061cffb..de8c25f96d1a347bb16443a56cbbcee3c4006421 100644
--- a/ppapi/api/ppb_message_loop.idl
+++ b/ppapi/api/ppb_message_loop.idl
@@ -37,6 +37,7 @@ label Chrome {
  *    - Call Run() with the message loop resource.
  *
  *   Your callacks should look like this:
+ *      @code

[dmichael (off chromium), 2013/03/28 21:56:50]

Is there any reason to not just always use <code> </code>?

[binji, 2013/03/28 22:02:24]

I haven't used doxygen much, but it seems like <code></code> does this: <CODE>
Starts a piece of text displayed in a typewriter font.
(see http://www.stack.nl/~dimitri/doxygen/manual/htmlcmds.html)

Whereas @code (or /code) does this:
Starts a block of code. A code block is treated differently from ordinary text.
It is interpreted as source code. The names of classes and members and other
documented entities are automatically replaced by links to the documentation...
(see http://www.stack.nl/~dimitri/doxygen/manual/commands.html#cmdcode)

  *      void DoMyWork(void* user_data, int32_t status) {
  *        if (status != PP_OK) {
  *          Cleanup();  // e.g. free user_data.
@@ -44,6 +45,7 @@ label Chrome {
  *        }
  *        ... do your work...
  *      }
+ *      @endcode
  * For a C++ example, see ppapi/utility/threading/simple_thread.h
  *
  * (You can also create the message loop resource on the background thread,