Use C++11 features in core/html

Source/core/html/HTMLCanvasElement.cpp

Index: Source/core/html/HTMLCanvasElement.cpp
diff --git a/Source/core/html/HTMLCanvasElement.cpp b/Source/core/html/HTMLCanvasElement.cpp
index f251bd5cf0b7c20519e04e5ed8d89827412f57ce..3eef4cc1a832ef2e52c94050f0fe14a128b7bde2 100644
--- a/Source/core/html/HTMLCanvasElement.cpp
+++ b/Source/core/html/HTMLCanvasElement.cpp
@@ -96,9 +96,8 @@ HTMLCanvasElement::~HTMLCanvasElement()
     resetDirtyRect();
     v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(-m_externallyAllocatedMemory);
 #if !ENABLE(OILPAN)
-    HashSet<RawPtr<CanvasObserver> >::iterator end = m_observers.end();
-    for (HashSet<RawPtr<CanvasObserver> >::iterator it = m_observers.begin(); it != end; ++it)
-        (*it)->canvasDestroyed(this);
+    for (const auto& canvasObserver : m_observers)

[Mike West, 2014/10/20 18:12:44]

When the type is trivial to type, please use the actual type rather than `const
auto&`. I know I didn't mention this on previous reviews; I didn't think about
it until I saw https://codereview.chromium.org/665613002/'s patch, which made a
lot of sense to me.

+        canvasObserver->canvasDestroyed(this);
     // Ensure these go away before the ImageBuffer.
     m_contextStateSaver.clear();
     m_context.clear();
@@ -251,9 +250,8 @@ void HTMLCanvasElement::willProcessTask()
 
 void HTMLCanvasElement::notifyObserversCanvasChanged(const FloatRect& rect)
 {
-    WillBeHeapHashSet<RawPtrWillBeWeakMember<CanvasObserver> >::iterator end = m_observers.end();
-    for (WillBeHeapHashSet<RawPtrWillBeWeakMember<CanvasObserver> >::iterator it = m_observers.begin(); it != end; ++it)
-        (*it)->canvasChanged(this, rect);
+    for (const auto& canvasObserver : m_observers)
+        canvasObserver->canvasChanged(this, rect);
 }
 
 void HTMLCanvasElement::reset()
@@ -311,9 +309,8 @@ void HTMLCanvasElement::reset()
         }
     }
 
-    WillBeHeapHashSet<RawPtrWillBeWeakMember<CanvasObserver> >::iterator end = m_observers.end();
-    for (WillBeHeapHashSet<RawPtrWillBeWeakMember<CanvasObserver> >::iterator it = m_observers.begin(); it != end; ++it)
-        (*it)->canvasResized(this);
+    for (const auto& canvasObserver : m_observers)
+        canvasObserver->canvasResized(this);
 }
 
 bool HTMLCanvasElement::paintsIntoCanvasBuffer() const