Add number() static methods to AtomicString class

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 ab2cac8fd3711c11546d0c00510ab383a08dbe7d..54152abd75e3cae8614175ea346ae798c4761062 100644
--- a/Source/core/html/HTMLCanvasElement.cpp
+++ b/Source/core/html/HTMLCanvasElement.cpp
@@ -132,12 +132,12 @@ void HTMLCanvasElement::removeObserver(CanvasObserver* observer)
 
 void HTMLCanvasElement::setHeight(int value)
 {
-    setAttribute(heightAttr, String::number(value));
+    setIntegralAttribute(heightAttr, value);
 }
 
 void HTMLCanvasElement::setWidth(int value)
 {
-    setAttribute(widthAttr, String::number(value));
+    setIntegralAttribute(widthAttr, value);
 }
 
 CanvasRenderingContext* HTMLCanvasElement::getContext(const String& type, CanvasContextAttributes* attrs)