Make scroll offset type of float in cc

cc/layers/layer.cc

Index: cc/layers/layer.cc
diff --git a/cc/layers/layer.cc b/cc/layers/layer.cc
index 1a22d9254a9b5bded9b1560c4769760efa57779d..e7e686669e9fa89aa3041ca8a08d81d665c75e65 100644
--- a/cc/layers/layer.cc
+++ b/cc/layers/layer.cc
@@ -654,7 +654,7 @@ void Layer::RemoveClipChild(Layer* child) {
   SetNeedsCommit();
 }
 
-void Layer::SetScrollOffset(gfx::Vector2d scroll_offset) {
+void Layer::SetScrollOffset(const gfx::ScrollOffset& scroll_offset) {
   DCHECK(IsPropertyChangeAllowed());
 
   if (scroll_offset_ == scroll_offset)
@@ -663,7 +663,8 @@ void Layer::SetScrollOffset(gfx::Vector2d scroll_offset) {
   SetNeedsCommit();
 }
 
-void Layer::SetScrollOffsetFromImplSide(const gfx::Vector2d& scroll_offset) {
+void Layer::SetScrollOffsetFromImplSide(
+    const gfx::ScrollOffset& scroll_offset) {
   DCHECK(IsPropertyChangeAllowed());
   // This function only gets called during a BeginMainFrame, so there
   // is no need to call SetNeedsUpdate here.
@@ -963,8 +964,9 @@ void Layer::PushPropertiesTo(LayerImpl* layer) {
     layer->SetScrollOffset(scroll_offset_);
   } else {
     layer->SetScrollOffsetAndDelta(
-        scroll_offset_, layer->ScrollDelta() - layer->sent_scroll_delta());
-    layer->SetSentScrollDelta(gfx::Vector2d());
+        scroll_offset_,
+        layer->ScrollDelta() - ToVector2dF(layer->sent_scroll_delta()));
+    layer->SetSentScrollDelta(gfx::ScrollOffset());
   }
 
   // Wrap the copy_requests_ in a PostTask to the main thread.