Add LayerTreeHostClient::{will,did}UpdateLayer, report layer updates to DevTools

cc/trees/layer_tree_host.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/trees/layer_tree_host.h"
 
 #include <algorithm>
 #include <stack>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "cc/animation/animation_registrar.h"
 #include "cc/animation/layer_animation_controller.h"
 #include "cc/base/math_util.h"
 #include "cc/debug/benchmark_instrumentation.h"
+#include "cc/debug/devtools_instrumentation.h"
 #include "cc/debug/overdraw_metrics.h"
 #include "cc/debug/rendering_stats_instrumentation.h"
 #include "cc/input/top_controls_manager.h"
 #include "cc/layers/heads_up_display_layer.h"
 #include "cc/layers/heads_up_display_layer_impl.h"
 #include "cc/layers/layer.h"
 #include "cc/layers/layer_iterator.h"
 #include "cc/layers/render_surface.h"
 #include "cc/layers/scrollbar_layer.h"
 #include "cc/resources/prioritized_resource_manager.h"
@@ skipping 35 matching lines @@
     LayerTreeHostClient* client,
     const LayerTreeSettings& settings,
     scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner) {
   scoped_ptr<LayerTreeHost> layer_tree_host(new LayerTreeHost(client,
                                                               settings));
   if (!layer_tree_host->Initialize(impl_task_runner))
     return scoped_ptr<LayerTreeHost>();
   return layer_tree_host.Pass();
 }
 
+static int s_next_tree_id = 1;
+
 LayerTreeHost::LayerTreeHost(LayerTreeHostClient* client,
                              const LayerTreeSettings& settings)
     : animating_(false),
       needs_full_tree_sync_(true),
       needs_filter_context_(false),
       client_(client),
       commit_number_(0),
       rendering_stats_instrumentation_(RenderingStatsInstrumentation::Create()),
       output_surface_can_be_initialized_(true),
       output_surface_lost_(true),
       num_failed_recreate_attempts_(0),
       settings_(settings),
       debug_state_(settings.initial_debug_state),
       overdraw_bottom_height_(0.f),
       device_scale_factor_(1.f),
       visible_(true),
       page_scale_factor_(1.f),
       min_page_scale_factor_(1.f),
       max_page_scale_factor_(1.f),
       trigger_idle_updates_(true),
       background_color_(SK_ColorWHITE),
       has_transparent_background_(false),
       partial_texture_update_requests_(0),
       in_paint_layer_contents_(false),
       total_frames_used_for_lcd_text_metrics_(0) {
   if (settings_.accelerated_animation_enabled)
     animation_registrar_ = AnimationRegistrar::Create();
   s_num_layer_tree_instances++;
-
+  if (s_next_tree_id <= 0)

[jamesr, 2013/07/22 18:01:02]

what is this for? are you expecting to allocate more than 2 billion layer tree
instances in the lifetime of one process?

[caseq, 2013/07/22 18:56:47]

This was mindlessly copied from layer.cc per Nat's suggestion above. I do wonder
on why we keep ids signed and avoid negatives as well. I'm happy to drop the
overflow check. Perhaps also make them unsigned?

+      s_next_tree_id = 1;
+  tree_id_ = s_next_tree_id++;
   rendering_stats_instrumentation_->set_record_rendering_stats(
       debug_state_.RecordRenderingStats());
 }
 
 bool LayerTreeHost::Initialize(
     scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner) {
   if (impl_task_runner.get())
     return InitializeProxy(ThreadProxy::Create(this, impl_task_runner));
   else
     return InitializeProxy(SingleThreadProxy::Create(this));
@@ skipping 761 matching lines @@
                                                ResourceUpdateQueue* queue,
                                                bool* did_paint_content,
                                                bool* need_more_updates) {
   // Note: Masks and replicas only exist for layers that own render surfaces. If
   // we reach this point in code, we already know that at least something will
   // be drawn into this render surface, so the mask and replica should be
   // painted.
 
   Layer* mask_layer = render_surface_layer->mask_layer();
   if (mask_layer) {
+    devtools_instrumentation::ScopedLayerTreeTask

[danakj, 2013/07/22 15:06:51]

Just wondering: Does devtools have the ability to use our trace events as well
for this kind of purpose? If so, would it make sense to use a TRACE_EVENT for
these instead?

[caseq, 2013/07/22 15:44:49]

Yes.
devtools_instrumentation::ScopedFooTask classes are wrappers for TRACE_EVENTx()
actually. We could use TRACE_EVENT directly, but given event and argument names
and types have special meaning for a different subsystem, we'd like to pretend
we have strongly-typed interface for these.

+        update_layer(devtools_instrumentation::kUpdateLayer,
+                     mask_layer->id(),
+                     id());
     *did_paint_content |= mask_layer->Update(queue, NULL);
     *need_more_updates |= mask_layer->NeedMoreUpdates();
   }
 
   Layer* replica_mask_layer =
       render_surface_layer->replica_layer() ?
       render_surface_layer->replica_layer()->mask_layer() : NULL;
   if (replica_mask_layer) {
+    devtools_instrumentation::ScopedLayerTreeTask
+        update_layer(devtools_instrumentation::kUpdateLayer,
+                     replica_mask_layer->id(),
+                     id());
     *did_paint_content |= replica_mask_layer->Update(queue, NULL);
     *need_more_updates |= replica_mask_layer->NeedMoreUpdates();
   }
 }
 
 void LayerTreeHost::PaintLayerContents(
     const RenderSurfaceLayerList& render_surface_layer_list,
     ResourceUpdateQueue* queue,
     bool* did_paint_content,
     bool* need_more_updates) {
@@ skipping 23 matching lines @@
            LayerIteratorType::Begin(&render_surface_layer_list);
        it != end;
        ++it) {
     bool prevent_occlusion = it.target_render_surface_layer()->HasCopyRequest();
     occlusion_tracker.EnterLayer(it, prevent_occlusion);
 
     if (it.represents_target_render_surface()) {
       PaintMasksForRenderSurface(
           *it, queue, did_paint_content, need_more_updates);
     } else if (it.represents_itself()) {
+      devtools_instrumentation::ScopedLayerTreeTask
+          update_layer(devtools_instrumentation::kUpdateLayer, it->id(), id());
       DCHECK(!it->paint_properties().bounds.IsEmpty());
       *did_paint_content |= it->Update(queue, &occlusion_tracker);
       *need_more_updates |= it->NeedMoreUpdates();
     }
 
     occlusion_tracker.LeaveLayer(it);
   }
 
   in_paint_layer_contents_ = false;
 
@@ skipping 114 matching lines @@
   for (AnimationRegistrar::AnimationControllerMap::iterator iter = copy.begin();
        iter != copy.end();
        ++iter) {
     (*iter).second->Animate(monotonic_time);
     bool start_ready_animations = true;
     (*iter).second->UpdateState(start_ready_animations, NULL);
   }
 }
 
 }  // namespace cc