Add use counters for lots of DOM APIs.

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

Index: third_party/WebKit/Source/core/dom/DocumentOrShadowRoot.idl
diff --git a/third_party/WebKit/Source/core/dom/DocumentOrShadowRoot.idl b/third_party/WebKit/Source/core/dom/DocumentOrShadowRoot.idl
index 676721575c83907eea7dc158a3581f2b7a0d7f4c..27ebc45a93bf0ebaaec908e24a7d045a429e4580 100644
--- a/third_party/WebKit/Source/core/dom/DocumentOrShadowRoot.idl
+++ b/third_party/WebKit/Source/core/dom/DocumentOrShadowRoot.idl
@@ -10,7 +10,7 @@
 ] interface DocumentOrShadowRoot {
     // Selection API
     // https://w3c.github.io/selection-api/#extensions-to-document-interface
-    Selection? getSelection();
+    [Measure] Selection? getSelection();
     // CSSOM View Module
     // https://dev.w3.org/csswg/cssom-view/#extensions-to-the-document-interface
     // TODO(foolip): The x and y arguments should be of type double.
@@ -20,7 +20,7 @@
     [SameObject] readonly attribute StyleSheetList styleSheets;
     // PointerLock API
     // https://w3c.github.io/pointerlock/
-    readonly attribute Element? pointerLockElement;
+    [Measure] readonly attribute Element? pointerLockElement;
     // Fullscreen API
     // https://fullscreen.spec.whatwg.org/
     [RuntimeEnabled=FullscreenUnprefixed] readonly attribute Element? fullscreenElement;