Add UseCounter for Document.registerElement()

BUG=383749
TEST=none

Review URL: https://codereview.chromium.org/330763002

git-svn-id: svn://svn.chromium.org/blink/trunk@176103 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/dom/Document.idl

@@ -204,7 +204,7 @@ typedef (CanvasRenderingContext2D or WebGLRenderingContext) RenderingContext;
                                                [Default=Undefined] optional float webkitForce);
     [RuntimeEnabled=Touch] TouchList createTouchList(Touch... touches);
 
-    [CallWith=ScriptState, CustomElementCallbacks, RaisesException] CustomElementConstructor registerElement(DOMString name, optional Dictionary options);
+    [CallWith=ScriptState, CustomElementCallbacks, RaisesException, MeasureAs=DocumentRegisterElement] CustomElementConstructor registerElement(DOMString name, optional Dictionary options);
     [CustomElementCallbacks, PerWorldBindings, LogActivity, RaisesException] Element createElement(DOMString localName, [TreatNullAs=NullString] DOMString typeExtension);
     [CustomElementCallbacks, PerWorldBindings, LogActivity, RaisesException] Element createElementNS([TreatNullAs=NullString] DOMString namespaceURI, DOMString qualifiedName,
                             [TreatNullAs=NullString] DOMString typeExtension);
@@ -224,4 +224,3 @@ typedef (CanvasRenderingContext2D or WebGLRenderingContext) RenderingContext;
 
 Document implements GlobalEventHandlers;
 Document implements ParentNode;
-

third_party/WebKit/Source/core/frame/UseCounter.h

@@ -454,6 +454,7 @@ public:
         WebkitEditableContentChangedOnNotNode = 454,
         HTMLImports = 455,
         ElementCreateShadowRoot = 456,
+        DocumentRegisterElement = 457,
         // Add new features immediately above this line. Don't change assigned
         // numbers of any item, and don't reuse removed slots.
         // Also, run update_use_counter_feature_enum.py in chromium/src/tools/metrics/histograms/