[PPAPI] Documentation fixes.

ppapi/api/ppb_message_loop.idl

 /* Copyright (c) 2012 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.
  */
 
 /**
  * Defines the PPB_MessageLoop interface.
  */
 label Chrome {
   M25 = 1.0
@@ skipping 19 matching lines @@
  *    - Create the thread yourself (using pthreads).
  *    - Create the message loop resource.
  *    - Pass the message loop resource to your thread's main function.
  *    - Call PostWork() on the message loop to run functions on the thread.
  *
  *   From the background thread's main function:
  *    - Call AttachToCurrentThread() with the message loop resource.
  *    - 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.
  *          return;
  *        }
  *        ... 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,
  * but then the main thread will have no reference to it should you want to
  * call PostWork()).
  *
  *
  * THREAD HANDLING
  *
  * The main thread has an implicitly created message loop. The main thread is
@@ skipping 203 matching lines @@
    *
    * @return
    *   - PP_OK: The request to quit was successfully posted.
    *   - PP_ERROR_BADRESOURCE: The message loop was invalid.
    *   - PP_ERROR_WRONG_THREAD: You are attempting to quit the main thread.
    *     The main thread's message loop is managed by the system and can't be
    *     quit.
    */
   int32_t PostQuit([in] PP_Resource message_loop, PP_Bool should_destroy);
 };