Add chrome.webstore API methods to allow sites to see progress of installation

chrome/browser/extensions/activity_log/activity_log.h

Index: chrome/browser/extensions/activity_log/activity_log.h
diff --git a/chrome/browser/extensions/activity_log/activity_log.h b/chrome/browser/extensions/activity_log/activity_log.h
index 84ffd397f6cf95a39659e5a262e7176a0f5189d1..b0087b259541313a6e6955fb32cab0fd4d5f61f2 100644
--- a/chrome/browser/extensions/activity_log/activity_log.h
+++ b/chrome/browser/extensions/activity_log/activity_log.h
@@ -82,20 +82,9 @@ class ActivityLog : public BrowserContextKeyedService,
   // Extension::InstallObserver
   // We keep track of whether the whitelisted extension is installed; if it is,
   // we want to recompute whether to have logging enabled.
-  virtual void OnExtensionInstalled(const Extension* extension) OVERRIDE {}

[felt, 2014/02/25 23:30:40]

Why is this disappearing with no replacement? Will this event no longer be
fired? It seems like this is going to break the AL.

[Devlin, 2014/02/25 23:40:46]

Shouldn't break it, I hope :)  Just removed the pure-virtualness of the
functions in InstallObserver, since usually consumers only needed to override a
few of them.  If they're overridden and not empty, they're still there.

On that note, though, unless I'm missing something, AL shouldn't care whether or
not this particular event is fired, right?  (It doesn't do anything here...)

[felt, 2014/02/25 23:43:41]

Ah, I see.

Also, it looks like someone has made previous changes that moved the Install
logic into Load... so nevermind anyway.

On 2014/02/25 23:40:46, D Cronin wrote:

   virtual void OnExtensionLoaded(const Extension* extension) OVERRIDE;
   virtual void OnExtensionUnloaded(const Extension* extension) OVERRIDE;
   virtual void OnExtensionUninstalled(const Extension* extension) OVERRIDE;
-  // We also have to list the following from InstallObserver.
-  virtual void OnBeginExtensionInstall(
-      const ExtensionInstallParams& params) OVERRIDE {}
-  virtual void OnDownloadProgress(const std::string& extension_id,
-                                  int percent_downloaded) OVERRIDE {}
-  virtual void OnInstallFailure(const std::string& extension_id) OVERRIDE {}
-  virtual void OnAppsReordered() OVERRIDE {}
-  virtual void OnAppInstalledToAppList(
-      const std::string& extension_id) OVERRIDE {}
-  virtual void OnShutdown() OVERRIDE {}
 
   // ApiActivityMonitor
   virtual void OnApiEventDispatched(