Use C++11 range-based loop for core/clipboard, core/dom and core/testing

Source/core/dom/ElementData.cpp

Index: Source/core/dom/ElementData.cpp
diff --git a/Source/core/dom/ElementData.cpp b/Source/core/dom/ElementData.cpp
index 8f24cdb5b2c5af7011a45edd42ef5602a482c295..020aa841e3cf1977589641137d4250ca4707e81c 100644
--- a/Source/core/dom/ElementData.cpp
+++ b/Source/core/dom/ElementData.cpp
@@ -114,10 +114,9 @@ bool ElementData::isEquivalent(const ElementData* other) const
     if (attributes.size() != otherAttributes.size())
         return false;
 
-    AttributeCollection::iterator end = attributes.end();
-    for (AttributeCollection::iterator it = attributes.begin(); it != end; ++it) {
-        const Attribute* otherAttr = otherAttributes.find(it->name());
-        if (!otherAttr || it->value() != otherAttr->value())
+    for (const Attribute& attribute : attributes) {
+        const Attribute* otherAttr = otherAttributes.find(attribute.name());
+        if (!otherAttr || attribute.value() != otherAttr->value())
             return false;
     }
     return true;