Make scroll offset type of float in cc

cc/blink/web_layer_impl.cc

Index: cc/blink/web_layer_impl.cc
diff --git a/cc/blink/web_layer_impl.cc b/cc/blink/web_layer_impl.cc
index c1f67fbed3af08fbe712b402c8c9e47b58a24ddb..960fed3243ca8a31a31374fe07ac7d447186e757 100644
--- a/cc/blink/web_layer_impl.cc
+++ b/cc/blink/web_layer_impl.cc
@@ -27,6 +27,7 @@
 #include "third_party/WebKit/public/platform/WebLayerScrollClient.h"
 #include "third_party/WebKit/public/platform/WebSize.h"
 #include "third_party/skia/include/utils/SkMatrix44.h"
+#include "ui/gfx/geometry/vector2d_conversions.h"
 
 using cc::Animation;
 using cc::Layer;
@@ -267,12 +268,21 @@ void WebLayerImpl::setForceRenderSurface(bool force_render_surface) {
   layer_->SetForceRenderSurface(force_render_surface);
 }
 
+void WebLayerImpl::setScrollPositionFloat(blink::WebFloatPoint position) {
+  layer_->SetScrollOffset(gfx::PointF(position).OffsetFromOrigin());
+}
+
+blink::WebFloatPoint WebLayerImpl::scrollPositionFloat() const {
+  return gfx::PointAtOffsetFromOrigin(layer_->scroll_offset());
+}
+
 void WebLayerImpl::setScrollPosition(blink::WebPoint position) {
   layer_->SetScrollOffset(gfx::Point(position).OffsetFromOrigin());
 }
 
 blink::WebPoint WebLayerImpl::scrollPosition() const {
-  return gfx::PointAtOffsetFromOrigin(layer_->scroll_offset());
+  return gfx::PointAtOffsetFromOrigin(
+      gfx::ToFlooredVector2d(layer_->scroll_offset()));
 }
 
 void WebLayerImpl::setScrollClipLayer(WebLayer* clip_layer) {