Introduce lock screen app context to extension features

extensions/renderer/script_context_set.h

Index: extensions/renderer/script_context_set.h
diff --git a/extensions/renderer/script_context_set.h b/extensions/renderer/script_context_set.h
index eddefb7c67a2ef0cc75d7c834a7a7a1c0a40b558..909703860e730743e6d06766d601186ca85d6dae 100644
--- a/extensions/renderer/script_context_set.h
+++ b/extensions/renderer/script_context_set.h
@@ -40,7 +40,7 @@ class ScriptContext;
 // changing underneath callers.
 class ScriptContextSet {
  public:
-  ScriptContextSet(
+  explicit ScriptContextSet(
       // Set of the IDs of extensions that are active in this process.
       // Must outlive this. TODO(kalman): Combine this and |extensions|.
       ExtensionIdSet* active_extension_ids);
@@ -106,6 +106,10 @@ class ScriptContextSet {
   // Cleans up contexts belonging to an unloaded extension.
   void OnExtensionUnloaded(const std::string& extension_id);
 
+  void set_is_lock_screen_context(bool is_lock_screen_context) {
+    is_lock_screen_context_ = is_lock_screen_context;
+  }
+
   // Adds the given |context| for testing purposes.
   void AddForTesting(std::unique_ptr<ScriptContext> context);
 
@@ -133,6 +137,10 @@ class ScriptContextSet {
   // The set of all ScriptContexts we own.
   std::set<ScriptContext*> contexts_;
 
+  // Whether the script context set is associated with the renderer active on
+  // the Chrome OS lock screen.
+  bool is_lock_screen_context_ = false;
+
   DISALLOW_COPY_AND_ASSIGN(ScriptContextSet);
 };