Added ability to dynamically toggle frame throttling in the scheduler.

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 d192a9aaa88d0fea68d586a193dda2f6e443fbc5..eb9aa850750eb3456905db139ed547892a879443 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -137,7 +137,8 @@ LayerTreeHost::LayerTreeHost(
       shared_bitmap_manager_(shared_bitmap_manager),
       gpu_memory_buffer_manager_(gpu_memory_buffer_manager),
       surface_id_namespace_(0u),
-      next_surface_sequence_(1u) {
+      next_surface_sequence_(1u),
+      swap_interval_(1) {
   if (settings_.accelerated_animation_enabled)
     animation_registrar_ = AnimationRegistrar::Create();
   rendering_stats_instrumentation_->set_record_rendering_stats(
@@ -741,6 +742,10 @@ void LayerTreeHost::SetVisible(bool visible) {
   proxy_->SetVisible(visible);
 }
 
+void LayerTreeHost::SetThrottleFrameProduction(bool throttle) {
+  proxy_->SetThrottleFrameProduction(throttle);
+}
+
 void LayerTreeHost::StartPageScaleAnimation(const gfx::Vector2d& target_offset,
                                             bool use_anchor,
                                             float scale,