Move NotificationObserver, NotificationSource, and NotificationDetails to content/public/browser.

This patch got way bigger than I wanted, but once I moved NotificationDetails, I figured I might as well mvoe the others since they're in the same files. In hindsight, I should have converted a subset of files at a time by leaving a using statement in the header.

BUG=98716
TBR=joi

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@106196 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/extensions/webstore_installer.h b/chrome/browser/extensions/webstore_installer.h
index cc06493..4c81089 100644
--- a/chrome/browser/extensions/webstore_installer.h
+++ b/chrome/browser/extensions/webstore_installer.h
@@ -10,14 +10,14 @@
 #include <vector>
 
 #include "base/compiler_specific.h"
-#include "content/common/notification_observer.h"
-#include "content/common/notification_registrar.h"
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
 
 class GURL;
 class Profile;
 
 // Downloads and installs extensions from the web store.
-class WebstoreInstaller : public NotificationObserver {
+class WebstoreInstaller : public content::NotificationObserver {
  public:
   enum Flag {
     FLAG_NONE = 0,
@@ -43,10 +43,10 @@
   // Note: the delegate should stay alive until being called back.
   void InstallExtension(const std::string& id, Delegate* delegate, int flags);
 
-  // NotificationObserver
+  // content::NotificationObserver
   virtual void Observe(int type,
-                       const NotificationSource& source,
-                       const NotificationDetails& details) OVERRIDE;
+                       const content::NotificationSource& source,
+                       const content::NotificationDetails& details) OVERRIDE;
 
  private:
   struct PendingInstall;
@@ -71,7 +71,7 @@
   // PendingInstall.
   void ReportSuccess(const std::string& id);
 
-  NotificationRegistrar registrar_;
+  content::NotificationRegistrar registrar_;
   Profile* profile_;
   std::vector<PendingInstall> pending_installs_;
 };