Revert "Revert "Const-ify RefCountedThreadSafe::AddRef and Release.""

chrome/common/net/url_request_context_getter.h

Index: chrome/common/net/url_request_context_getter.h
diff --git a/chrome/common/net/url_request_context_getter.h b/chrome/common/net/url_request_context_getter.h
index 2b6ea82fce57e945daf8fb42687eff2109bdab2d..ade5e1a21b36a457683cb07490b9909c1fa9fa00 100644
--- a/chrome/common/net/url_request_context_getter.h
+++ b/chrome/common/net/url_request_context_getter.h
@@ -33,7 +33,8 @@ class URLRequestContextGetter
   // Returns a MessageLoopProxy corresponding to the thread on which the
   // request IO happens (the thread on which the returned URLRequestContext
   // may be used).
-  virtual scoped_refptr<base::MessageLoopProxy> GetIOMessageLoopProxy() = 0;
+  virtual scoped_refptr<base::MessageLoopProxy>
+      GetIOMessageLoopProxy() const = 0;
 
   // Controls whether or not the URLRequestContextGetter considers itself to be
   // the the "main" URLRequestContextGetter.  Note that each Profile will have a
@@ -44,7 +45,7 @@ class URLRequestContextGetter
   void set_is_main(bool is_main) { is_main_ = is_main; }
 
  protected:
-  friend class DeleteTask<URLRequestContextGetter>;
+  friend class DeleteTask<const URLRequestContextGetter>;
   friend struct URLRequestContextGetterTraits;
 
   URLRequestContextGetter();
@@ -55,7 +56,7 @@ class URLRequestContextGetter
  private:
   // OnDestruct is meant to ensure deletion on the thread on which the request
   // IO happens.
-  void OnDestruct();
+  void OnDestruct() const;
 
   // Indicates whether or not this is the default URLRequestContextGetter for
   // the main Profile.
@@ -63,7 +64,7 @@ class URLRequestContextGetter
 };
 
 struct URLRequestContextGetterTraits {
-  static void Destruct(URLRequestContextGetter* context_getter) {
+  static void Destruct(const URLRequestContextGetter* context_getter) {
     context_getter->OnDestruct();
   }
 };