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

Source/core/dom/StyleEngine.cpp

Index: Source/core/dom/StyleEngine.cpp
diff --git a/Source/core/dom/StyleEngine.cpp b/Source/core/dom/StyleEngine.cpp
index 031c0a6fffc89a0590ca5b85933e95f1a38d7b7d..db446de6529a36e4dad5cc71f46dd0116aeb4fe5 100644
--- a/Source/core/dom/StyleEngine.cpp
+++ b/Source/core/dom/StyleEngine.cpp
@@ -346,8 +346,8 @@ bool StyleEngine::shouldUpdateShadowTreeStyleSheetCollection(StyleResolverUpdate
 
 void StyleEngine::clearMediaQueryRuleSetOnTreeScopeStyleSheets(TreeScopeSet treeScopes)
 {
-    for (TreeScopeSet::iterator it = treeScopes.begin(); it != treeScopes.end(); ++it) {
-        TreeScope& treeScope = **it;
+    for (auto& scope : treeScopes) {

[Julien - ping for review, 2015/01/02 09:42:02]

auto == TreeScope*

I think it's OK to do a pointer copy here as it makes it really clear what's
going on and write:

for (TreeScope* scope : treeScopes) {

[zhaoze.zhou, 2015/01/05 15:17:57]

Done.

+        TreeScope& treeScope = *scope;
         ASSERT(treeScope != m_document);
         ShadowTreeStyleSheetCollection* collection = static_cast<ShadowTreeStyleSheetCollection*>(styleSheetCollectionFor(treeScope));
         ASSERT(collection);
@@ -386,8 +386,7 @@ void StyleEngine::updateActiveStyleSheets(StyleResolverUpdateMode updateMode)
         TreeScopeSet treeScopes = updateMode == FullStyleUpdate ? m_activeTreeScopes : m_dirtyTreeScopes;
         HashSet<TreeScope*> treeScopesRemoved;
 
-        for (TreeScopeSet::iterator it = treeScopes.begin(); it != treeScopes.end(); ++it) {
-            TreeScope* treeScope = *it;
+        for (auto* treeScope : treeScopes) {

[Julien - ping for review, 2015/01/02 09:42:02]

Similar comment.

[zhaoze.zhou, 2015/01/05 15:17:57]

Done.

             ASSERT(treeScope != m_document);
             ShadowTreeStyleSheetCollection* collection = static_cast<ShadowTreeStyleSheetCollection*>(styleSheetCollectionFor(*treeScope));
             ASSERT(collection);