Make scroll offset type of float in cc

cc/layers/layer_impl.cc

Index: cc/layers/layer_impl.cc
diff --git a/cc/layers/layer_impl.cc b/cc/layers/layer_impl.cc
index 5b39eb0e36262c2299be2fd73522def8ab8c897c..b8b919c7618f44fd152e4185dd318a2f6ab8fe24 100644
--- a/cc/layers/layer_impl.cc
+++ b/cc/layers/layer_impl.cc
@@ -354,7 +354,7 @@ ResourceProvider::ResourceId LayerImpl::ContentsResourceId() const {
   return 0;
 }
 
-void LayerImpl::SetSentScrollDelta(const gfx::Vector2d& sent_scroll_delta) {
+void LayerImpl::SetSentScrollDelta(const gfx::Vector2dF& sent_scroll_delta) {
   // Pending tree never has sent scroll deltas
   DCHECK(layer_tree_impl()->IsActiveTree());
 
@@ -400,7 +400,7 @@ void LayerImpl::ApplySentScrollDeltasFromAbortedCommit() {
   // whether a delegate is being used.
   scroll_offset_ += sent_scroll_delta_;
   scroll_delta_ -= sent_scroll_delta_;
-  sent_scroll_delta_ = gfx::Vector2d();
+  sent_scroll_delta_ = gfx::Vector2dF();
 }
 
 void LayerImpl::ApplyScrollDeltasSinceBeginMainFrame() {
@@ -539,7 +539,7 @@ void LayerImpl::PushPropertiesTo(LayerImpl* layer) {
   layer->set_user_scrollable_vertical(user_scrollable_vertical_);
   layer->SetScrollOffsetAndDelta(
       scroll_offset_, layer->ScrollDelta() - layer->sent_scroll_delta());
-  layer->SetSentScrollDelta(gfx::Vector2d());
+  layer->SetSentScrollDelta(gfx::Vector2dF());
   layer->Set3dSortingContextId(sorting_context_id_);
   layer->SetNumDescendantsThatDrawContent(num_descendants_that_draw_content_);
 
@@ -1078,11 +1078,11 @@ bool LayerImpl::IsExternalFlingActive() const {
          scroll_offset_delegate_->IsExternalFlingActive();
 }
 
-void LayerImpl::SetScrollOffset(const gfx::Vector2d& scroll_offset) {
+void LayerImpl::SetScrollOffset(const gfx::Vector2dF& scroll_offset) {
   SetScrollOffsetAndDelta(scroll_offset, ScrollDelta());
 }
 
-void LayerImpl::SetScrollOffsetAndDelta(const gfx::Vector2d& scroll_offset,
+void LayerImpl::SetScrollOffsetAndDelta(const gfx::Vector2dF& scroll_offset,
                                         const gfx::Vector2dF& scroll_delta) {
   bool changed = false;