Remove ExtensionPrefs's dependency on ChromeAppSorting.

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 b99b3661d6b6d0d3f9d51fbe5c8215c2912685e3..01b6aabd4e732fef136c860750ab10e27826e0e8 100644
--- a/extensions/browser/extensions_browser_client.h
+++ b/extensions/browser/extensions_browser_client.h
@@ -5,12 +5,16 @@
 #ifndef EXTENSIONS_BROWSER_EXTENSIONS_BROWSER_CLIENT_H_
 #define EXTENSIONS_BROWSER_EXTENSIONS_BROWSER_CLIENT_H_
 
+#include "base/memory/scoped_ptr.h"
+
 namespace content {
 class BrowserContext;
 }
 
 namespace extensions {
 
+class AppSorting;
+
 // Interface to allow the extensions module to make browser-process-specific
 // queries of the embedder. Should be Set() once in the browser process.
 //
@@ -57,6 +61,9 @@ class ExtensionsBrowserClient {
   // version for later comparison.
   virtual bool DidVersionUpdate(content::BrowserContext* context) = 0;
 
+  // Creates a new AppSorting instance.
+  virtual scoped_ptr<AppSorting> CreateAppSorting() = 0;
+
   // Returns the single instance of |this|.
   static ExtensionsBrowserClient* Get();