Track tasks run by task runner wrapper

Chained tasks and async tasks are traced using the wrapper class name.
Add trace events to track these tasks

BUG=1136635

Change-Id: Ibafce336fbfc4f7491bd196b93b92bf42ad143e4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2491402Reviewed-by: Tommy Nyquist <nyquist@chromium.org>
Commit-Queue: ssid <ssid@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821440}

base/android/java/src/org/chromium/base/task/AsyncTask.java

@@ -51,7 +51,7 @@ public abstract class AsyncTask<Result> {
     private static final StealRunnableHandler STEAL_RUNNABLE_HANDLER = new StealRunnableHandler();
 
     private final Callable<Result> mWorker;
-    private final FutureTask<Result> mFuture;
+    private final NamedFutureTask mFuture;
 
     private volatile @Status int mStatus = Status.PENDING;
 
@@ -397,6 +397,14 @@ public abstract class AsyncTask<Result> {
             return AsyncTask.this.getClass();
         }
 
+        @Override
+        @SuppressWarnings("NoDynamicStringsInTraceEventCheck")
+        public void run() {
+            try (TraceEvent e = TraceEvent.scoped("AsyncTask.run: " + mFuture.getBlamedClass())) {
+                super.run();
+            }
+        }
+
         @Override
         protected void done() {
             try {

chrome/android/java/src/org/chromium/chrome/browser/init/ChainedTasks.java

@@ -7,6 +7,7 @@ package org.chromium.chrome.browser.init;
 import android.util.Pair;
 
 import org.chromium.base.ThreadUtils;
+import org.chromium.base.TraceEvent;
 import org.chromium.base.task.PostTask;
 import org.chromium.base.task.TaskTraits;
 
@@ -27,10 +28,14 @@ public class ChainedTasks {
 
     private final Runnable mRunAndPost = new Runnable() {
         @Override
+        @SuppressWarnings("NoDynamicStringsInTraceEventCheck")
         public void run() {
             if (mTasks.isEmpty()) return;
             Pair<TaskTraits, Runnable> pair = mTasks.pop();
-            pair.second.run();
+            try (TraceEvent e = TraceEvent.scoped(
+                         "ChainedTask.run: " + pair.second.getClass().getName())) {
+                pair.second.run();
+            }
             if (!mTasks.isEmpty()) PostTask.postTask(mTasks.peek().first, this);
         }
     };