Move compositor thread input handling logic into content

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index efcc5295465539f182d6628e1092abb1ea3989fe..fbbb0388b8b771499b5109df0d74aea0366404a4 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -159,6 +159,7 @@ LayerTreeHostImpl::LayerTreeHostImpl(
     RenderingStatsInstrumentation* rendering_stats_instrumentation)
     : client_(client),
       proxy_(proxy),
+      input_handler_client_(NULL),
       did_lock_scrolling_layer_(false),
       should_bubble_scrolls_(false),
       wheel_scrolling_(false),
@@ -208,6 +209,11 @@ LayerTreeHostImpl::~LayerTreeHostImpl() {
   TRACE_EVENT0("cc", "LayerTreeHostImpl::~LayerTreeHostImpl()");
   TRACE_EVENT_OBJECT_DELETED_WITH_ID("cc.debug", "cc::LayerTreeHostImpl", this);
 
+  if (input_handler_client_) {
+    input_handler_client_->WillShutdown();
+    input_handler_client_ = NULL;
+  }
+
   if (active_tree_->root_layer()) {
     ClearRenderSurfaces();
     // The layer trees must be destroyed before the layer tree host. We've
@@ -275,6 +281,8 @@ bool LayerTreeHostImpl::CanDraw() {
 
 void LayerTreeHostImpl::Animate(base::TimeTicks monotonic_time,
                                 base::Time wall_clock_time) {
+  if (input_handler_client_)
+    input_handler_client_->Animate(monotonic_time);
   AnimatePageScale(monotonic_time);
   AnimateLayers(monotonic_time, wall_clock_time);
   AnimateScrollbars(monotonic_time);
@@ -721,6 +729,11 @@ bool LayerTreeHostImpl::CalculateRenderPasses(FrameData* frame) {
   return draw_frame;
 }
 
+void LayerTreeHostImpl::MainThreadHasStoppedFlinging() {
+  if (input_handler_client_)
+    input_handler_client_->MainThreadHasStoppedFlinging();
+}
+
 void LayerTreeHostImpl::UpdateBackgroundAnimateTicking(
     bool should_background_tick) {
   bool enabled = should_background_tick &&
@@ -1475,6 +1488,11 @@ bool LayerTreeHostImpl::EnsureRenderSurfaceLayerList() {
   return !active_tree_->RenderSurfaceLayerList().empty();
 }
 
+void LayerTreeHostImpl::BindToClient(InputHandlerClient* client) {
+  DCHECK(input_handler_client_ == NULL);
+  input_handler_client_ = client;
+}
+
 InputHandler::ScrollStatus LayerTreeHostImpl::ScrollBegin(
     gfx::Point viewport_point, InputHandler::ScrollInputType type) {
   TRACE_EVENT0("cc", "LayerTreeHostImpl::ScrollBegin");