TaskManager: Remove some unused/unnecessary methods.

chrome/browser/task_manager/extension_process_resource_provider.cc

Index: chrome/browser/task_manager/extension_process_resource_provider.cc
diff --git a/chrome/browser/task_manager/extension_process_resource_provider.cc b/chrome/browser/task_manager/extension_process_resource_provider.cc
index 33fae4514630555e2ff5308235162828c77004c0..f06165d7de8fb5acbc486ecd6539afd14e4d1901 100644
--- a/chrome/browser/task_manager/extension_process_resource_provider.cc
+++ b/chrome/browser/task_manager/extension_process_resource_provider.cc
@@ -53,15 +53,16 @@ class ExtensionProcessResource : public Resource {
   virtual void Inspect() const OVERRIDE;
   virtual bool SupportNetworkUsage() const OVERRIDE;
   virtual void SetSupportNetworkUsage() OVERRIDE;
-  virtual const extensions::Extension* GetExtension() const OVERRIDE;
 
   // Returns the pid of the extension process.
   int process_id() const { return pid_; }
 
+ private:
+  const extensions::Extension* GetExtension() const;
+
   // Returns true if the associated extension has a background page.
-  virtual bool IsBackground() const OVERRIDE;
+  bool IsBackground() const;
 
- private:
   // The icon painted for the extension process.
   static gfx::ImageSkia* default_icon_;