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..5eb60ccbf8d1135109fec3ad28c5d579ceef23a7 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 +268,23 @@ void WebLayerImpl::setForceRenderSurface(bool force_render_surface) {
   layer_->SetForceRenderSurface(force_render_surface);
 }
 
+void WebLayerImpl::setScrollPositionFloat(
+    blink::WebDoublePoint position) {
+  layer_->SetScrollOffset(gfx::ScrollOffset(position.x, position.y));
+}
+
+blink::WebDoublePoint WebLayerImpl::scrollPositionFloat() const {
+  return blink::WebDoublePoint(layer_->scroll_offset().x(),
+                               layer_->scroll_offset().y());
+}
+
 void WebLayerImpl::setScrollPosition(blink::WebPoint position) {
-  layer_->SetScrollOffset(gfx::Point(position).OffsetFromOrigin());
+  layer_->SetScrollOffset(gfx::ScrollOffset(position.x, position.y));
 }
 
 blink::WebPoint WebLayerImpl::scrollPosition() const {
-  return gfx::PointAtOffsetFromOrigin(layer_->scroll_offset());
+  return gfx::PointAtOffsetFromOrigin(
+      (layer_->scroll_offset()).ToFlooredVector2d());
 }
 
 void WebLayerImpl::setScrollClipLayer(WebLayer* clip_layer) {