Make PointerEvent coordinates fractional for touch

third_party/WebKit/Source/core/events/MouseEvent.idl

Index: third_party/WebKit/Source/core/events/MouseEvent.idl
diff --git a/third_party/WebKit/Source/core/events/MouseEvent.idl b/third_party/WebKit/Source/core/events/MouseEvent.idl
index 99172320ccde0916bcc8fa2e4c02ff2422be5254..2b14c72c30aebecf86f555fe5d39fdfa8030913a 100644
--- a/third_party/WebKit/Source/core/events/MouseEvent.idl
+++ b/third_party/WebKit/Source/core/events/MouseEvent.idl
@@ -23,10 +23,10 @@
     Constructor(DOMString type, optional MouseEventInit eventInitDict),
     ConstructorCallWith=ScriptState,
 ] interface MouseEvent : UIEvent {
-    readonly attribute long             screenX;
-    readonly attribute long             screenY;
-    readonly attribute long             clientX;
-    readonly attribute long             clientY;
+    readonly attribute double           screenX;
+    readonly attribute double           screenY;
+    readonly attribute double           clientX;
+    readonly attribute double           clientY;
     readonly attribute boolean          ctrlKey;
     readonly attribute boolean          shiftKey;
     readonly attribute boolean          altKey;