Revert of Implement scroll handler latency tracking

cc/trees/layer_tree_host.cc

Index: cc/trees/layer_tree_host.cc
diff --git a/cc/trees/layer_tree_host.cc b/cc/trees/layer_tree_host.cc
index 6d9e2362d48e10c4193242ff71441045a668932d..ed7472d638ba891a70e9ae04a6384fc70068fde8 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -1032,40 +1032,31 @@
   in_paint_layer_contents_ = false;
 }
 
-void LayerTreeHost::ApplyScrollAndScale(ScrollAndScaleSet* info) {
+void LayerTreeHost::ApplyScrollAndScale(const ScrollAndScaleSet& info) {
   if (!root_layer_.get())
     return;
-
-  ScopedPtrVector<SwapPromise>::iterator it = info->swap_promises.begin();
-  for (; it != info->swap_promises.end(); ++it) {
-    scoped_ptr<SwapPromise> swap_promise(info->swap_promises.take(it));
-    TRACE_EVENT_FLOW_STEP0("input",
-                           "LatencyInfo.Flow",
-                           TRACE_ID_DONT_MANGLE(swap_promise->TraceId()),
-                           "Main thread scroll update");
-    QueueSwapPromise(swap_promise.Pass());
-  }
 
   gfx::Vector2d inner_viewport_scroll_delta;
   gfx::Vector2d outer_viewport_scroll_delta;
 
-  for (size_t i = 0; i < info->scrolls.size(); ++i) {
-    Layer* layer = LayerTreeHostCommon::FindLayerInSubtree(
-        root_layer_.get(), info->scrolls[i].layer_id);
+  for (size_t i = 0; i < info.scrolls.size(); ++i) {
+    Layer* layer =
+        LayerTreeHostCommon::FindLayerInSubtree(root_layer_.get(),
+                                                info.scrolls[i].layer_id);
     if (!layer)
       continue;
     if (layer == outer_viewport_scroll_layer_.get()) {
-      outer_viewport_scroll_delta += info->scrolls[i].scroll_delta;
+      outer_viewport_scroll_delta += info.scrolls[i].scroll_delta;
     } else if (layer == inner_viewport_scroll_layer_.get()) {
-      inner_viewport_scroll_delta += info->scrolls[i].scroll_delta;
+      inner_viewport_scroll_delta += info.scrolls[i].scroll_delta;
     } else {
       layer->SetScrollOffsetFromImplSide(layer->scroll_offset() +
-                                         info->scrolls[i].scroll_delta);
+                                         info.scrolls[i].scroll_delta);
     }
   }
 
   if (!inner_viewport_scroll_delta.IsZero() ||
-      !outer_viewport_scroll_delta.IsZero() || info->page_scale_delta != 1.f) {
+      !outer_viewport_scroll_delta.IsZero() || info.page_scale_delta != 1.f) {
     // SetScrollOffsetFromImplSide above could have destroyed the tree,
     // so re-get this layer before doing anything to it.
 
@@ -1082,11 +1073,11 @@
           outer_viewport_scroll_layer_->scroll_offset() +
           outer_viewport_scroll_delta);
     }
-    ApplyPageScaleDeltaFromImplSide(info->page_scale_delta);
+    ApplyPageScaleDeltaFromImplSide(info.page_scale_delta);
 
     client_->ApplyScrollAndScale(
         inner_viewport_scroll_delta + outer_viewport_scroll_delta,
-        info->page_scale_delta);
+        info.page_scale_delta);
   }
 }