Fix comment.

ppapi/c/ppb_graphics_2d.h

 /* Copyright (c) 2010 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.
  */
 #ifndef PPAPI_C_PPB_GRAPHICS_2D_H_
 #define PPAPI_C_PPB_GRAPHICS_2D_H_
 
 #include "ppapi/c/pp_bool.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_module.h"
@@ skipping 104 matching lines @@
    *
    * The new image must be the exact same size as this graphics context. If the
    * new image uses a different image format than the browser's native bitmap
    * format (use PPB_ImageData.GetNativeImageDataFormat to retrieve this), then
    * a conversion will be done inside the browser which may slow the performance
    * a little bit.
    *
    * THE NEW IMAGE WILL NOT BE PAINTED UNTIL YOU CALL FLUSH.
    *
    * After this call, you should take care to release your references to the
-   * image. If you paint to the image after a Swap, there is the possibility of
-   * significant painting artifacts because the page might use partially-
-   * rendered data when copying out of the backing store.
+   * image. If you paint to the image after ReplaceContents, there is the
+   * possibility of significant painting artifacts because the page might use
+   * partially-rendered data when copying out of the backing store.
    *
    * In the case of an animation, you will want to allocate a new image for the
    * next frame. It is best if you wait until the flush callback has executed
    * before allocating this bitmap. This gives the browser the option of
    * caching the previous backing store and handing it back to you (assuming
    * the sizes match). In the optimal case, this means no bitmaps are allocated
    * during the animation, and the backing store and "front buffer" (which the
    * plugin is painting into) are just being swapped back and forth.
    */
   void (*ReplaceContents)(PP_Resource graphics_2d, PP_Resource image_data);
 
   /**
-   * Flushes any enqueued paint, scroll, and swap commands for the backing
+   * Flushes any enqueued paint, scroll, and replace commands for the backing
    * store. This actually executes the updates, and causes a repaint of the
    * webpage, assuming this graphics context is bound to a plugin instance. This
    * can run in two modes:
    *
    * - In synchronous mode, you specify NULL for the callback and the callback
    *   data. This function will block the calling thread until the image has
    *   been painted to the screen. It is not legal to block the main thread of
    *   the plugin, you can use synchronous mode only from background threads.
    *
    * - In asynchronous mode, you specify a callback function and the argument
@@ skipping 65 matching lines @@
                    struct PP_CompletionCallback callback);
 
 };
 
 /**
  * @}
  * End addtogroup PPB
  */
 #endif  /* PPAPI_C_PPB_GRAPHICS_2D_H_ */