[DevTools] Add minimum size to WebInspector.View.

Source/devtools/front_end/DOMExtension.js

Index: Source/devtools/front_end/DOMExtension.js
diff --git a/Source/devtools/front_end/DOMExtension.js b/Source/devtools/front_end/DOMExtension.js
index 05e3fa305c8ca4547688088a3dfac68e1e1c9cdb..70df32c8ae5f936aaa3d253a21bf13b910cceac1 100644
--- a/Source/devtools/front_end/DOMExtension.js
+++ b/Source/devtools/front_end/DOMExtension.js
@@ -206,6 +206,15 @@ function Size(width, height)
 }
 
 /**
+ * @param {?Size} size
+ * @return {boolean}
+ */
+Size.prototype.isEqual = function(size)
+{
+    return !!size && this.width === size.width && this.height === size.height;
+};
+
+/**
  * @param {?Element=} containerElement
  * @return {!Size}
  */