Remove PlatformGestureEvent in favour of using WebGestureEvent

third_party/WebKit/Source/platform/scroll/ScrollTypes.h

Index: third_party/WebKit/Source/platform/scroll/ScrollTypes.h
diff --git a/third_party/WebKit/Source/platform/scroll/ScrollTypes.h b/third_party/WebKit/Source/platform/scroll/ScrollTypes.h
index 32f9ff2de0afa1bb19faec67be084cea8067ffb6..32d22c8071fd1e62bd29df498131f24396e2de42 100644
--- a/third_party/WebKit/Source/platform/scroll/ScrollTypes.h
+++ b/third_party/WebKit/Source/platform/scroll/ScrollTypes.h
@@ -27,6 +27,7 @@
 #define ScrollTypes_h
 
 #include "platform/geometry/FloatPoint.h"
+#include "public/platform/WebGestureEvent.h"
 #include "wtf/Assertions.h"
 
 namespace blink {
@@ -249,6 +250,21 @@ inline ScrollOffset toScrollDelta(ScrollDirectionPhysical dir, float delta) {
                                                    : ScrollOffset(0, delta);
 }
 
+inline ScrollGranularity toPlatformScrollGranularity(
+    WebGestureEvent::ScrollUnits units) {
+  switch (units) {
+    case WebGestureEvent::ScrollUnits::PrecisePixels:
+      return ScrollGranularity::ScrollByPrecisePixel;
+    case WebGestureEvent::ScrollUnits::Pixels:
+      return ScrollGranularity::ScrollByPixel;
+    case WebGestureEvent::ScrollUnits::Page:
+      return ScrollGranularity::ScrollByPage;
+    default:
+      NOTREACHED();
+      return ScrollGranularity::ScrollByPrecisePixel;
+  }
+}
+
 typedef unsigned ScrollbarControlPartMask;
 
 }  // namespace blink