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

chrome_frame/metrics_service.cc

Index: chrome_frame/metrics_service.cc
diff --git a/chrome_frame/metrics_service.cc b/chrome_frame/metrics_service.cc
index 461862f57eab9dd42abb7a776b03ea3799773ac9..881c74cbcc707908e87e58510e276acba90e1b6c 100644
--- a/chrome_frame/metrics_service.cc
+++ b/chrome_frame/metrics_service.cc
@@ -210,7 +210,7 @@ class ChromeFrameUploadRequestContextGetter : public URLRequestContextGetter {
     return context_;
   }
 
-  virtual scoped_refptr<base::MessageLoopProxy> GetIOMessageLoopProxy() {
+  virtual scoped_refptr<base::MessageLoopProxy> GetIOMessageLoopProxy() const {
     if (!io_message_loop_proxy_.get()) {
       io_message_loop_proxy_ = base::MessageLoopProxy::CreateForCurrentThread();
     }
@@ -223,7 +223,7 @@ class ChromeFrameUploadRequestContextGetter : public URLRequestContextGetter {
   }
 
   scoped_refptr<URLRequestContext> context_;
-  scoped_refptr<base::MessageLoopProxy> io_message_loop_proxy_;
+  mutable scoped_refptr<base::MessageLoopProxy> io_message_loop_proxy_;
   MessageLoop* io_loop_;
 };