Add support for omnibox.onInputStarted and onInputCancelled.

chrome/browser/extensions/extension_omnibox_api.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 CHROME_BROWSER_EXTENSIONS_EXTENSION_OMNIBOX_API_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_OMNIBOX_API_H_
 
 #include "base/string16.h"
 #include "chrome/browser/autocomplete/autocomplete.h"
 #include "chrome/browser/extensions/extension_function.h"
 
 // Event router class for events related to the omnibox API.
 class ExtensionOmniboxEventRouter {
  public:
+  // The user has just typed the omnibox keyword. This is sent exactly once in
+  // a given input session, before any OnInputChanged events.
+  static void OnInputStarted(
+      Profile* profile, const std::string& extension_id);
+
   // The user has changed what is typed into the omnibox while in an extension
   // keyword session. Returns true if someone is listening to this event, and
   // thus we have some degree of confidence we'll get a response.
   static bool OnInputChanged(
       Profile* profile, const std::string& extension_id,
       const std::string& input, int suggest_id);
 
   // The user has accepted the omnibox input.
   static void OnInputEntered(
       Profile* profile, const std::string& extension_id,
       const std::string& input);
 
+  // The user has cleared the keyword, or closed the omnibox popup. This is
+  // sent at most once in a give input session, after any OnInputChanged events.
+  static void OnInputCancelled(
+      Profile* profile, const std::string& extension_id);
+
  private:
   DISALLOW_COPY_AND_ASSIGN(ExtensionOmniboxEventRouter);
 };
 
 class OmniboxSendSuggestionsFunction : public SyncExtensionFunction {
  public:
   virtual bool RunImpl();
   DECLARE_EXTENSION_FUNCTION_NAME("experimental.omnibox.sendSuggestions");
 };
 
 struct ExtensionOmniboxSuggestion {
   // The text that gets put in the edit box.
   string16 content;
 
   // The text that is displayed in the drop down.
   string16 description;
 
   // Contains style ranges for the description.
   ACMatchClassifications description_styles;
 };
 
 struct ExtensionOmniboxSuggestions {
   int request_id;
   std::vector<ExtensionOmniboxSuggestion> suggestions;
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_OMNIBOX_API_H_