Revert "Move ExtensionCache to //extensions"

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 5b3b1d2a13a6cba57cf5b514792ce9b68b03c0bc..5ef97ff48aecae6add724ffbd2422b861b5324c8 100644
--- a/extensions/browser/extensions_browser_client.h
+++ b/extensions/browser/extensions_browser_client.h
@@ -38,7 +38,6 @@ class ApiActivityMonitor;
 class AppSorting;
 class ComponentExtensionResourceManager;
 class Extension;
-class ExtensionCache;
 class ExtensionHostDelegate;
 class ExtensionPrefsObserver;
 class ExtensionSystem;
@@ -188,9 +187,6 @@ class ExtensionsBrowserClient {
   // Returns the embedder's net::NetLog.
   virtual net::NetLog* GetNetLog() = 0;
 
-  // Gets the single ExtensionCache instance shared across the browser process.
-  virtual ExtensionCache* GetExtensionCache() = 0;
-
   // Returns the single instance of |this|.
   static ExtensionsBrowserClient* Get();