Make PointerEvent coordinates fractional for touch

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

Index: third_party/WebKit/Source/core/events/MouseEventInit.idl
diff --git a/third_party/WebKit/Source/core/events/MouseEventInit.idl b/third_party/WebKit/Source/core/events/MouseEventInit.idl
index fa367cbce4484c205fcbd5c7efae598d525e80af..512d249c0dc95c67f0ac68f85c5435687603dde8 100644
--- a/third_party/WebKit/Source/core/events/MouseEventInit.idl
+++ b/third_party/WebKit/Source/core/events/MouseEventInit.idl
@@ -5,10 +5,10 @@
 // https://w3c.github.io/uievents/#idl-def-MouseEventInit
 
 dictionary MouseEventInit : EventModifierInit {
-    long screenX = 0;
-    long screenY = 0;
-    long clientX = 0;
-    long clientY = 0;
+    double screenX = 0;
+    double screenY = 0;
+    double clientX = 0;
+    double clientY = 0;
     short button = 0;
     unsigned short buttons = 0;
     EventTarget? relatedTarget = null;