Use BrowserContext as key in API. Switch Autofill to use BC in place of Profile.

chrome/browser/api/prefs/pref_service_base.h

Index: chrome/browser/api/prefs/pref_service_base.h
diff --git a/chrome/browser/api/prefs/pref_service_base.h b/chrome/browser/api/prefs/pref_service_base.h
index dbdb051652bea3cf2503b4984c5ba9c73b6425e6..0827c2cc49f4484cb4b00b986c8c74ceb98cf1d0 100644
--- a/chrome/browser/api/prefs/pref_service_base.h
+++ b/chrome/browser/api/prefs/pref_service_base.h
@@ -19,6 +19,7 @@
 #include "base/values.h"
 
 namespace content {
+class BrowserContext;
 class NotificationObserver;
 }
 
@@ -32,8 +33,8 @@ class TabContents;
 
 class PrefServiceBase {
  public:
-  // Retrieves a PrefServiceBase for the given profile.
-  static PrefServiceBase* ForProfile(Profile* profile);
+  // Retrieves a PrefServiceBase for the given context.
+  static PrefServiceBase* ForContext(content::BrowserContext* context);
 
   virtual ~PrefServiceBase() {}