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

extensions/renderer/extension_injection_host.cc

Index: extensions/renderer/extension_injection_host.cc
diff --git a/extensions/renderer/extension_injection_host.cc b/extensions/renderer/extension_injection_host.cc
index a3783d94f20e0d4ebd83eb7f64be9f0b440cb6a1..58654e729c62abf10f4564c8651651b958556da9 100644
--- a/extensions/renderer/extension_injection_host.cc
+++ b/extensions/renderer/extension_injection_host.cc
@@ -16,7 +16,7 @@ ExtensionInjectionHost::ExtensionInjectionHost(
 ExtensionInjectionHost::~ExtensionInjectionHost() {
 }
 
-const std::string& ExtensionInjectionHost::GetContentSecurityPolicy() const {
+std::string ExtensionInjectionHost::GetContentSecurityPolicy() const {
   return CSPInfo::GetContentSecurityPolicy(extension_.get());
 }
 
@@ -55,4 +55,8 @@ PermissionsData::AccessType ExtensionInjectionHost::CanExecuteOnFrame(
   }
 }
 
+bool ExtensionInjectionHost::IsGone() const {
+  return extension_.get() == nullptr;
+}
+
 }  // namespace extensions