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

cc/base/devtools_instrumentation.h

Index: cc/base/devtools_instrumentation.h
diff --git a/cc/base/devtools_instrumentation.h b/cc/base/devtools_instrumentation.h
index 40e2d9efd708851bbb56a374b094ec57048c9008..6ea2f7a454c42eeafc1b1bfc35c13433a8896702 100644
--- a/cc/base/devtools_instrumentation.h
+++ b/cc/base/devtools_instrumentation.h
@@ -58,9 +58,14 @@ class CC_BASE_EXPORT ScopedLayerTask {
 class CC_BASE_EXPORT ScopedImageDecodeTask {
  public:
   enum Type { SOFTWARE, GPU };
-
-  ScopedImageDecodeTask(const void* imagePtr, Type type)
-      : type_(type), start_time_(base::TimeTicks::Now()) {
+  enum DecodeTaskType { IN_RASTER, CHECKER_IMAGING, JS_DECODE_API };
+
+  ScopedImageDecodeTask(const void* imagePtr,
+                        Type type,
+                        DecodeTaskType task_type)
+      : type_(type),
+        task_type_(task_type),
+        start_time_(base::TimeTicks::Now()) {
     TRACE_EVENT_BEGIN1(internal::kCategory, internal::kImageDecodeTask,
                        internal::kPixelRefId,
                        reinterpret_cast<uint64_t>(imagePtr));
@@ -68,20 +73,54 @@ class CC_BASE_EXPORT ScopedImageDecodeTask {
   ~ScopedImageDecodeTask() {
     TRACE_EVENT_END0(internal::kCategory, internal::kImageDecodeTask);
     base::TimeDelta duration = base::TimeTicks::Now() - start_time_;
-    switch (type_) {
-      case SOFTWARE:
-        UMA_HISTOGRAM_COUNTS_1M("Renderer4.ImageDecodeTaskDurationUs.Software",
-                                duration.InMicroseconds());
+    switch (task_type_) {
+      case IN_RASTER:
+        switch (type_) {
+          case SOFTWARE:
+            UMA_HISTOGRAM_COUNTS_1M(
+                "Renderer4.ImageDecodeTaskDurationUs.Software",
+                duration.InMicroseconds());
+            break;
+          case GPU:
+            UMA_HISTOGRAM_COUNTS_1M("Renderer4.ImageDecodeTaskDurationUs.Gpu",
+                                    duration.InMicroseconds());
+            break;
+        }
+        break;
+      case CHECKER_IMAGING:
+        switch (type_) {
+          case SOFTWARE:
+            UMA_HISTOGRAM_COUNTS_1M(
+                "Renderer4.ImageDecodeTaskDurationUs.CheckerImaging.Software",
+                duration.InMicroseconds());
+            break;
+          case GPU:
+            UMA_HISTOGRAM_COUNTS_1M(
+                "Renderer4.ImageDecodeTaskDurationUs.CheckerImaging.Gpu",
+                duration.InMicroseconds());
+            break;
+        }
         break;
-      case GPU:
-        UMA_HISTOGRAM_COUNTS_1M("Renderer4.ImageDecodeTaskDurationUs.Gpu",
-                                duration.InMicroseconds());
+      case JS_DECODE_API:
+        switch (type_) {
+          case SOFTWARE:
+            UMA_HISTOGRAM_COUNTS_1M(
+                "Renderer4.ImageDecodeTaskDurationUs.JSDecode.Software",
+                duration.InMicroseconds());
+            break;
+          case GPU:
+            UMA_HISTOGRAM_COUNTS_1M(
+                "Renderer4.ImageDecodeTaskDurationUs.JSDecode.Gpu",
+                duration.InMicroseconds());
+            break;
+        }
         break;
     }
   }
 
  private:
   const Type type_;
+  const DecodeTaskType task_type_;
   const base::TimeTicks start_time_;
   DISALLOW_COPY_AND_ASSIGN(ScopedImageDecodeTask);
 };