DevTools: add LazyPixelRef id to ImageDecodeTask event

... so we can relate ImageDecode events to image element reference and
resource URL.
Related blink change: https://codereview.chromium.org/24096002

BUG=
R=ernstm@chromium.org, nduca@chromium.org

Review URL: https://codereview.chromium.org/23537033

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224691 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 18 insertions, 3 deletions

diff --git a/cc/debug/devtools_instrumentation.h b/cc/debug/devtools_instrumentation.h
index 7a77d40..eea9e62 100644
--- a/cc/debug/devtools_instrumentation.h
+++ b/cc/debug/devtools_instrumentation.h
@@ -14,11 +14,13 @@ namespace internal {
 const char kCategory[] = "cc,devtools";
 const char kLayerId[] = "layerId";
 const char kLayerTreeId[] = "layerTreeId";
+const char kPixelRefId[] = "pixelRefId";
+
+const char kImageDecodeTask[] = "ImageDecodeTask";
 }
 
 const char kPaintLayer[] = "PaintLayer";
 const char kRasterTask[] = "RasterTask";
-const char kImageDecodeTask[] = "ImageDecodeTask";
 const char kPaintSetup[] = "PaintSetup";
 const char kUpdateLayer[] = "UpdateLayer";
 
@@ -38,6 +40,19 @@ class ScopedLayerTask {
   DISALLOW_COPY_AND_ASSIGN(ScopedLayerTask);
 };
 
+class ScopedImageDecodeTask {
+ public:
+  explicit ScopedImageDecodeTask(void* pixelRef) {
+    TRACE_EVENT_BEGIN1(internal::kCategory, internal::kImageDecodeTask,
+        internal::kPixelRefId, reinterpret_cast<uint64>(pixelRef));
+  }
+  ~ScopedImageDecodeTask() {
+    TRACE_EVENT_END0(internal::kCategory, internal::kImageDecodeTask);
+  }
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ScopedImageDecodeTask);
+};
+
 class ScopedLayerTreeTask {
  public:
   ScopedLayerTreeTask(const char* event_name,
diff --git a/cc/resources/raster_worker_pool.cc b/cc/resources/raster_worker_pool.cc
index 6f80cc3..2df3d442 100644
--- a/cc/resources/raster_worker_pool.cc
+++ b/cc/resources/raster_worker_pool.cc
@@ -268,8 +268,8 @@ class ImageDecodeWorkerPoolTaskImpl : public internal::WorkerPoolTask {
   // Overridden from internal::WorkerPoolTask:
   virtual void RunOnWorkerThread(unsigned thread_index) OVERRIDE {
     TRACE_EVENT0("cc", "ImageDecodeWorkerPoolTaskImpl::RunOnWorkerThread");
-    devtools_instrumentation::ScopedLayerTask image_decode_task(
-        devtools_instrumentation::kImageDecodeTask, layer_id_);
+    devtools_instrumentation::ScopedImageDecodeTask image_decode_task(
+        pixel_ref_);
     base::TimeTicks start_time = rendering_stats_->StartRecording();
     pixel_ref_->Decode();
     base::TimeDelta duration = rendering_stats_->EndRecording(start_time);