Set up the infrastructure for Extension event metrics.

extensions/browser/event_router.h

 // 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.
 
 #ifndef EXTENSIONS_BROWSER_EVENT_ROUTER_H_
 #define EXTENSIONS_BROWSER_EVENT_ROUTER_H_
 
 #include <map>
 #include <set>
 #include <string>
 #include <utility>
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/containers/hash_tables.h"
 #include "base/memory/linked_ptr.h"
 #include "base/memory/ref_counted.h"
 #include "base/scoped_observer.h"
 #include "base/values.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/render_process_host_observer.h"
 #include "extensions/browser/event_listener_map.h"
+#include "extensions/browser/extension_event_histogram_value.h"
 #include "extensions/browser/extension_registry_observer.h"
 #include "extensions/common/event_filtering_info.h"
 #include "ipc/ipc_sender.h"
 
 class GURL;
 class PrefService;
 
 namespace content {
 class BrowserContext;
 class RenderProcessHost;
@@ skipping 293 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(EventRouter);
 };
 
 struct Event {
   // This callback should return true if the event should be dispatched to the
   // given context and extension, and false otherwise.
   typedef base::Callback<bool(content::BrowserContext*,
                               const Extension*,
                               base::ListValue*)> WillDispatchCallback;
 
+  // The identifier for the event, for histograms. In most cases this
+  // correlates 1:1 with |event_name|, in some cases events will generate
+  // their own names, but they cannot generate their own identifier.
+  events::HistogramValue histogram_value;
+
   // The event to dispatch.
   std::string event_name;
 
   // Arguments to send to the event listener.
   scoped_ptr<base::ListValue> event_args;
 
   // If non-NULL, then the event will not be sent to other BrowserContexts
   // unless the extension has permission (e.g. incognito tab update -> normal
   // tab only works if extension is allowed incognito access).
   content::BrowserContext* restrict_to_browser_context;
@@ skipping 11 matching lines @@
   // If specified, this is called before dispatching an event to each
   // extension. The third argument is a mutable reference to event_args,
   // allowing the caller to provide different arguments depending on the
   // extension and profile. This is guaranteed to be called synchronously with
   // DispatchEvent, so callers don't need to worry about lifetime.
   //
   // NOTE: the Extension argument to this may be NULL because it's possible for
   // this event to be dispatched to non-extension processes, like WebUI.
   WillDispatchCallback will_dispatch_callback;
 
-  Event(const std::string& event_name,
+  Event(events::HistogramValue histogram_value,
+        const std::string& event_name,
         scoped_ptr<base::ListValue> event_args);
 
-  Event(const std::string& event_name,
+  Event(events::HistogramValue histogram_value,
+        const std::string& event_name,
         scoped_ptr<base::ListValue> event_args,
         content::BrowserContext* restrict_to_browser_context);
 
-  Event(const std::string& event_name,
+  Event(events::HistogramValue histogram_value,
+        const std::string& event_name,
         scoped_ptr<base::ListValue> event_args,
         content::BrowserContext* restrict_to_browser_context,
         const GURL& event_url,
         EventRouter::UserGestureState user_gesture,
         const EventFilteringInfo& info);
 
   ~Event();
 
   // Makes a deep copy of this instance. Ownership is transferred to the
   // caller.
@@ skipping 10 matching lines @@
   const std::string event_name;
 
   const std::string extension_id;
   const GURL listener_url;
   content::BrowserContext* browser_context;
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_EVENT_ROUTER_H_