cc: Add UMA for tracking decode duration for out of raster decodes.

cc/base/devtools_instrumentation.cc

Index: cc/base/devtools_instrumentation.cc
diff --git a/cc/base/devtools_instrumentation.cc b/cc/base/devtools_instrumentation.cc
index 010b16149f1459263c3938514eddacda4b1dd75d..cbf47b35d4f5d796172527648188fc494e43319e 100644
--- a/cc/base/devtools_instrumentation.cc
+++ b/cc/base/devtools_instrumentation.cc
@@ -30,5 +30,50 @@ extern const char kCompositeLayers[] = "CompositeLayers";
 extern const char kPaintSetup[] = "PaintSetup";
 extern const char kUpdateLayer[] = "UpdateLayer";
 
+ScopedImageDecodeTask::ScopedImageDecodeTask(const void* image_ptr,
+                                             DecodeType decode_type,
+                                             TaskType task_type)
+    : decode_type_(decode_type),
+      task_type_(task_type),
+      start_time_(base::TimeTicks::Now()) {
+  TRACE_EVENT_BEGIN1(internal::kCategory, internal::kImageDecodeTask,
+                     internal::kPixelRefId,
+                     reinterpret_cast<uint64_t>(image_ptr));
+}
+
+ScopedImageDecodeTask::~ScopedImageDecodeTask() {
+  TRACE_EVENT_END0(internal::kCategory, internal::kImageDecodeTask);
+  base::TimeDelta duration = base::TimeTicks::Now() - start_time_;
+  switch (task_type_) {
+    case kInRaster:
+      switch (decode_type_) {
+        case kSoftware:
+          UMA_HISTOGRAM_COUNTS_1M(
+              "Renderer4.ImageDecodeTaskDurationUs.Software",
+              duration.InMicroseconds());
+          break;
+        case kGpu:
+          UMA_HISTOGRAM_COUNTS_1M("Renderer4.ImageDecodeTaskDurationUs.Gpu",
+                                  duration.InMicroseconds());
+          break;
+      }
+      break;
+    case kOutOfRaster:
+      switch (decode_type_) {
+        case kSoftware:
+          UMA_HISTOGRAM_COUNTS_1M(
+              "Renderer4.ImageDecodeTaskDurationUs.OutOfRaster.Software",
+              duration.InMicroseconds());
+          break;
+        case kGpu:
+          UMA_HISTOGRAM_COUNTS_1M(
+              "Renderer4.ImageDecodeTaskDurationUs.OutOfRaster.Gpu",
+              duration.InMicroseconds());
+          break;
+      }
+      break;
+  }
+}
+
 }  // namespace devtools_instrumentation
 }  // namespace cc