Add use counters for lots of DOM APIs.

third_party/WebKit/Source/core/clipboard/DataTransferItem.idl

Index: third_party/WebKit/Source/core/clipboard/DataTransferItem.idl
diff --git a/third_party/WebKit/Source/core/clipboard/DataTransferItem.idl b/third_party/WebKit/Source/core/clipboard/DataTransferItem.idl
index f30a2ca71e0059420af7d81a84681153c99eef60..14422d3ace178c80df61d2472589b6f94060b119 100644
--- a/third_party/WebKit/Source/core/clipboard/DataTransferItem.idl
+++ b/third_party/WebKit/Source/core/clipboard/DataTransferItem.idl
@@ -31,10 +31,10 @@
 // https://html.spec.whatwg.org/#the-datatransferitem-interface
 
 interface DataTransferItem {
-    readonly attribute DOMString kind;
-    readonly attribute DOMString type;
+    [Measure] readonly attribute DOMString kind;
+    [Measure] readonly attribute DOMString type;
     // TODO(foolip): The callback argument should be a FunctionStringCallback.
-    [CallWith=ExecutionContext] void getAsString(StringCallback? callback);
+    [CallWith=ExecutionContext, Measure] void getAsString(StringCallback? callback);
     // TODO(foolip): getAsFile() should return a File object. crbug.com/361145
-    Blob? getAsFile();
+    [Measure] Blob? getAsFile();
 };