[inspector] async stacks for Promise.then calls...

test/inspector/debugger/async-instrumentation.js

Index: test/inspector/debugger/async-instrumentation.js
diff --git a/test/inspector/debugger/async-instrumentation.js b/test/inspector/debugger/async-instrumentation.js
new file mode 100644
index 0000000000000000000000000000000000000000..380bbd427dbae589d8dd36c1666f515f99c7d022
--- /dev/null
+++ b/test/inspector/debugger/async-instrumentation.js
@@ -0,0 +1,64 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+print('Checks async instrumentation enabled in the middle.');
+
+InspectorTest.addScript(`
+function foo() {
+  // asyncTaskStarted
+  debugger;
+  // asyncTaskFinished
+  debugger;
+}
+
+function test() {
+  var resolve1;
+  var p1 = new Promise(resolve => resolve1 = resolve);
+  var p2 = p1.then(foo);
+  debugger;
+  resolve1(); // asyncTaskScheduled
+  debugger;
+  return p2;
+}
+
+//# sourceURL=test.js`, 7, 26);
+
+InspectorTest.setupScriptMap();
+Protocol.Debugger.onPaused(message => {
+  if (enableOnPause-- === 0)
+    Protocol.Debugger.setAsyncCallStackDepth({ maxDepth: 128 });
+  InspectorTest.logCallFrames(message.params.callFrames);
+  var asyncStackTrace = message.params.asyncStackTrace;
+  while (asyncStackTrace) {
+    InspectorTest.log(`-- ${asyncStackTrace.description} --`);
+    InspectorTest.logCallFrames(asyncStackTrace.callFrames);
+    asyncStackTrace = asyncStackTrace.parent;
+  }
+  InspectorTest.log('');
+  Protocol.Debugger.resume();
+});
+
+Protocol.Debugger.enable();
+InspectorTest.runTestSuite([
+  function beforeAsyncTaskScheduled(next) {
+    enableOnPause = 0;
+    Protocol.Runtime.evaluate({ expression: 'test()//# sourceURL=expr1.js', awaitPromise: true })
+      .then(() => Protocol.Debugger.setAsyncCallStackDepth({ maxDepth: 0 }))
+      .then(next);
+  },
+
+  function afterAsyncTaskScheduled(next) {
+    enableOnPause = 2;
+    Protocol.Runtime.evaluate({ expression: 'test()//# sourceURL=expr1.js', awaitPromise: true })
+      .then(() => Protocol.Debugger.setAsyncCallStackDepth({ maxDepth: 0 }))
+      .then(next);
+  },
+
+  function afterAsyncTaskStarted(next) {
+    enableOnPause = 3;
+    Protocol.Runtime.evaluate({ expression: 'test()//# sourceURL=expr1.js', awaitPromise: true })
+      .then(() => Protocol.Debugger.setAsyncCallStackDepth({ maxDepth: 0 }))
+      .then(next);
+  }
+]);