TaskManager: Remove some unused/unnecessary methods.

chrome/browser/task_manager/background_resource_provider.cc

Index: chrome/browser/task_manager/background_resource_provider.cc
diff --git a/chrome/browser/task_manager/background_resource_provider.cc b/chrome/browser/task_manager/background_resource_provider.cc
index 4e72f904e0b61bbaaac307f19381cfb86b14ab33..292326ba2df13de41c5c8d39ace851028512c0b1 100644
--- a/chrome/browser/task_manager/background_resource_provider.cc
+++ b/chrome/browser/task_manager/background_resource_provider.cc
@@ -48,7 +48,6 @@ class BackgroundContentsResource : public RendererResource {
   virtual base::string16 GetTitle() const OVERRIDE;
   virtual base::string16 GetProfileName() const OVERRIDE;
   virtual gfx::ImageSkia GetIcon() const OVERRIDE;
-  virtual bool IsBackground() const OVERRIDE;
 
   const base::string16& application_name() const { return application_name_; }
  private:
@@ -115,10 +114,6 @@ gfx::ImageSkia BackgroundContentsResource::GetIcon() const {
   return *default_icon_;
 }
 
-bool BackgroundContentsResource::IsBackground() const {
-  return true;
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // BackgroundContentsResourceProvider class
 ////////////////////////////////////////////////////////////////////////////////