Refactoring: de-couple Extensions from "script injection System" [render side]:3

extensions/renderer/extension_injection_host.h

Index: extensions/renderer/extension_injection_host.h
diff --git a/extensions/renderer/extension_injection_host.h b/extensions/renderer/extension_injection_host.h
index 42e27332a0e41c67d3de15b98200c3950bfb52d0..b98a853e5636a22cb28fd061c001d279e84f8ef2 100644
--- a/extensions/renderer/extension_injection_host.h
+++ b/extensions/renderer/extension_injection_host.h
@@ -20,7 +20,7 @@ class ExtensionInjectionHost : public InjectionHost {
 
  private:
   // InjectionHost:
-  const std::string& GetContentSecurityPolicy() const override;
+  std::string GetContentSecurityPolicy() const override;
   const GURL& url() const override;
   const std::string& name() const override;
   PermissionsData::AccessType CanExecuteOnFrame(
@@ -28,6 +28,7 @@ class ExtensionInjectionHost : public InjectionHost {
       const GURL& top_frame_url,
       int tab_id,
       bool is_declarative) const override;
+  bool IsGone() const override;
 
   scoped_refptr<const Extension> extension_;