cc: add DevTools instrumentation for impl-side frames

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 da8b47e4bac176f877772e2e0cb4583269bb44cd..786d88563e68fabf0a109ab34cefddedb1cfc51b 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -19,6 +19,7 @@
 #include "cc/base/util.h"
 #include "cc/debug/benchmark_instrumentation.h"
 #include "cc/debug/debug_rect_history.h"
+#include "cc/debug/devtools_instrumentation.h"
 #include "cc/debug/frame_rate_counter.h"
 #include "cc/debug/overdraw_metrics.h"
 #include "cc/debug/paint_time_counter.h"
@@ -189,9 +190,10 @@ scoped_ptr<LayerTreeHostImpl> LayerTreeHostImpl::Create(
     LayerTreeHostImplClient* client,
     Proxy* proxy,
     RenderingStatsInstrumentation* rendering_stats_instrumentation,
-    SharedBitmapManager* manager) {
+    SharedBitmapManager* manager,
+    int id) {
   return make_scoped_ptr(new LayerTreeHostImpl(
-      settings, client, proxy, rendering_stats_instrumentation, manager));
+      settings, client, proxy, rendering_stats_instrumentation, manager, id));
 }
 
 LayerTreeHostImpl::LayerTreeHostImpl(
@@ -199,7 +201,8 @@ LayerTreeHostImpl::LayerTreeHostImpl(
     LayerTreeHostImplClient* client,
     Proxy* proxy,
     RenderingStatsInstrumentation* rendering_stats_instrumentation,
-    SharedBitmapManager* manager)
+    SharedBitmapManager* manager,
+    int id)
     : client_(client),
       proxy_(proxy),
       input_handler_client_(NULL),
@@ -236,7 +239,8 @@ LayerTreeHostImpl::LayerTreeHostImpl(
       animation_registrar_(AnimationRegistrar::Create()),
       rendering_stats_instrumentation_(rendering_stats_instrumentation),
       need_to_update_visible_tiles_before_draw_(false),
-      shared_bitmap_manager_(manager) {
+      shared_bitmap_manager_(manager),
+      id_(id) {
   DCHECK(proxy_->IsImplThread());
   DidVisibilityChange(this, visible_);
 
@@ -1553,6 +1557,8 @@ void LayerTreeHostImpl::ActivatePendingTree() {
 
   if (time_source_client_adapter_ && time_source_client_adapter_->Active())
     DCHECK(active_tree_->root_layer());
+  devtools_instrumentation::didActivateLayerTree(id_,
+      active_tree_->source_frame_number());
 }
 
 void LayerTreeHostImpl::SetVisible(bool visible) {