Use C++11 range-based loop in core/fetch

Source/core/fetch/ResourceClientWalker.h

Index: Source/core/fetch/ResourceClientWalker.h
diff --git a/Source/core/fetch/ResourceClientWalker.h b/Source/core/fetch/ResourceClientWalker.h
index 0bc60567402505e9f034e566f13bf92d8e7ee216..3f35eca9dacde177a12cfeebc2c48e8cd790ed47 100644
--- a/Source/core/fetch/ResourceClientWalker.h
+++ b/Source/core/fetch/ResourceClientWalker.h
@@ -38,11 +38,9 @@ public:
     ResourceClientWalker(const HashCountedSet<ResourceClient*>& set)
         : m_clientSet(set), m_clientVector(set.size()), m_index(0)
     {
-        typedef HashCountedSet<ResourceClient*>::const_iterator Iterator;
-        Iterator end = set.end();
         size_t clientIndex = 0;
-        for (Iterator current = set.begin(); current != end; ++current)
-            m_clientVector[clientIndex++] = current->key;
+        for (const auto& resourceClient : set)
+            m_clientVector[clientIndex++] = resourceClient.key;
     }
 
     T* next()