fix spelling of comments

ppapi/c/ppp_instance.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_PPP_INSTANCE_H_
 #define PPAPI_C_PPP_INSTANCE_H_
 
 #include "ppapi/c/pp_bool.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_rect.h"
@@ skipping 102 matching lines @@
    */
   void (*DidChangeFocus)(PP_Instance instance, PP_Bool has_focus);
 
   /**
    * This value represents a pointer to a function to handle input events.
    * Returns true if the event was handled or false if it was not.
    *
    * If the event was handled, it will not be forwarded to the web page or
    * browser. If it was not handled, it will bubble according to the normal
    * rules. So it is important that a module respond accurately with whether
-   * event propogation should continue.
+   * event propagation should continue.
    *
-   * Event propogation also controls focus. If you handle an event like a mouse
+   * Event propagation also controls focus. If you handle an event like a mouse
    * event, typically your module will be given focus. Returning false means
    * that the click will be given to a lower part of the page and your module
    * will not receive focus. This allows a module to be partially transparent,
    * where clicks on the transparent areas will behave like clicks to the
    * underlying page.
    * @param[in] instance A PP_Instance indentifying one instance of a module.
    * @param[in] event The event.
    * @return PP_TRUE if @a event was handled, PP_FALSE otherwise.
    */
   PP_Bool (*HandleInputEvent)(PP_Instance instance,
@@ skipping 36 matching lines @@
    * @return A PP_Var containing scriptable object.
    */
   struct PP_Var (*GetInstanceObject)(PP_Instance instance);
 };
 /**
  * @}
  */
 
 #endif  /* PPAPI_C_PPP_INSTANCE_H_ */