Cleanup: make ExtensionRequestSender manage its IPC responses directly, rather

base/scoped_observer.h

Index: base/scoped_observer.h
diff --git a/base/scoped_observer.h b/base/scoped_observer.h
index d273e338cdb13cc10b1a4bb006674695dc4b72f6..ceada319b99017c41838ea99914af2174cb8d189 100644
--- a/base/scoped_observer.h
+++ b/base/scoped_observer.h
@@ -19,6 +19,11 @@ class ScopedObserver {
  public:
   explicit ScopedObserver(Observer* observer) : observer_(observer) {}
 
+  // Creates with an initial |source|.
+  ScopedObserver(Observer* observer, Source* source) : observer_(observer) {
+    Add(source);
+  }
+
   ~ScopedObserver() {
     for (size_t i = 0; i < sources_.size(); ++i)
       sources_[i]->RemoveObserver(observer_);
@@ -30,7 +35,7 @@ class ScopedObserver {
     source->AddObserver(observer_);
   }
 
-  // Removse the object passed to the constructor as an observer from |source|.
+  // Removes the object passed to the constructor as an observer from |source|.
   void Remove(Source* source) {
     sources_.erase(std::find(sources_.begin(), sources_.end(), source));
     source->RemoveObserver(observer_);