Add ApiActivityMonitor to decouple ActivityLog from low-level extensions code

extensions/browser/extensions_browser_client.h

Index: extensions/browser/extensions_browser_client.h
diff --git a/extensions/browser/extensions_browser_client.h b/extensions/browser/extensions_browser_client.h
index ee7fde39724aadff5ce711de389302aec7f8b00f..7cff76d58cd3fed2440caf7c3ff8bf9ecc428081 100644
--- a/extensions/browser/extensions_browser_client.h
+++ b/extensions/browser/extensions_browser_client.h
@@ -21,6 +21,7 @@ class WebContents;
 
 namespace extensions {
 
+class ApiActivityMonitor;
 class AppSorting;
 class ExtensionSystem;
 
@@ -96,6 +97,11 @@ class ExtensionsBrowserClient {
   // does not support JavaScript dialogs.
   virtual content::JavaScriptDialogManager* GetJavaScriptDialogManager() = 0;
 
+  // Returns the embedder's ApiActivityMonitor for |context|. Returns NULL if
+  // the embedder does not monitor extension API activity.
+  virtual ApiActivityMonitor* GetApiActivityMonitor(
+      content::BrowserContext* context) = 0;
+
   // Returns the dependencies of ExtensionSystem. May return an empty list.
   virtual std::vector<BrowserContextKeyedServiceFactory*>
       GetExtensionSystemDependencies() = 0;