Revert of [inspector] avoid cloning of async call chains

test/inspector/debugger/async-stacks-limit.js

Index: test/inspector/debugger/async-stacks-limit.js
diff --git a/test/inspector/debugger/async-stacks-limit.js b/test/inspector/debugger/async-stacks-limit.js
new file mode 100644
index 0000000000000000000000000000000000000000..62206750df58875112fc1c84587423002077f533
--- /dev/null
+++ b/test/inspector/debugger/async-stacks-limit.js
@@ -0,0 +1,164 @@
+// 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.
+
+InspectorTest.log('Checks that async stacks works good with different limits');
+
+InspectorTest.addScript(`
+var resolveTest;
+
+function foo1() {
+  debugger;
+}
+
+function foo2() {
+  debugger;
+  if (resolveTest) resolveTest();
+}
+
+function promise() {
+  var resolve1;
+  var p1 = new Promise(resolve => resolve1 = resolve);
+  var p2 = p1.then(foo1);
+  resolve1();
+  return p2;
+}
+
+function twoPromises() {
+  var resolve1;
+  var resolve2;
+  var p1 = new Promise(resolve => resolve1 = resolve);
+  var p2 = new Promise(resolve => resolve2 = resolve);
+  var p3 = p1.then(foo1);
+  var p4 = p2.then(foo2);
+  resolve1();
+  resolve2();
+  return Promise.all([p3, p4]);
+}
+
+function twoSetTimeout() {
+  setTimeout(foo1, 0);
+  setTimeout(foo2, 0);
+  return new Promise(resolve => resolveTest = resolve);
+}
+
+function twentySetTimeout() {
+  var resolve1;
+  var p1 = new Promise(resolve => resolve1 = resolve);
+  for (var i = 1; i <= 19; ++i)
+    setTimeout('(function foo' + i + '(){debugger;})()',0);
+  setTimeout(resolve1, 0);
+  return p1;
+}
+
+//# sourceURL=test.js`, 7, 26);
+
+InspectorTest.setupScriptMap();
+Protocol.Debugger.onPaused(message => {
+  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();
+Protocol.Debugger.setAsyncCallStackDepth({ maxDepth: 128 });
+InspectorTest.runTestSuite([
+  function testZeroLimit(next) {
+    Protocol.Runtime.evaluate({
+        expression: 'setMaxAsyncTaskStacks(0)//# sourceURL=expr.js'})
+      .then(() => Protocol.Runtime.evaluate({
+        expression: 'promise()//# sourceURL=expr.js', awaitPromise: true
+      }))
+      .then(() => cancelAllAsyncTasks())
+      .then(next);
+  },
+
+  function testTwoLimit(next) {
+    // we need one stack for parent task and one for next task.
+    Protocol.Runtime
+        .evaluate({expression: 'setMaxAsyncTaskStacks(2)//# sourceURL=expr.js'})
+        .then(() => Protocol.Runtime.evaluate({
+          expression: 'promise()//# sourceURL=expr.js',
+          awaitPromise: true
+        }))
+        .then(() => cancelAllAsyncTasks())
+        .then(next);
+  },
+
+  function testOneLimitTwoPromises(next) {
+    // Should be no async stacks because when first microtask is finished
+    // it will resolve and schedule p3 - will remove async stack for scheduled
+    // p2.
+    Protocol.Runtime.evaluate({
+        expression: 'setMaxAsyncTaskStacks(1)//# sourceURL=expr.js'})
+      .then(() => Protocol.Runtime.evaluate({
+        expression: 'twoPromises()//# sourceURL=expr.js', awaitPromise: true
+      }))
+      .then(() => cancelAllAsyncTasks())
+      .then(next);
+  },
+
+  function testFourLimitTwoPromises(next) {
+    Protocol.Runtime
+        .evaluate({expression: 'setMaxAsyncTaskStacks(4)//# sourceURL=expr.js'})
+        .then(() => Protocol.Runtime.evaluate({
+          expression: 'twoPromises()//# sourceURL=expr.js',
+          awaitPromise: true
+        }))
+        .then(() => cancelAllAsyncTasks())
+        .then(next);
+  },
+
+  function testSixLimitTwoPromises(next) {
+    Protocol.Runtime
+        .evaluate({expression: 'setMaxAsyncTaskStacks(6)//# sourceURL=expr.js'})
+        .then(() => Protocol.Runtime.evaluate({
+          expression: 'twoPromises()//# sourceURL=expr.js',
+          awaitPromise: true
+        }))
+        .then(() => cancelAllAsyncTasks())
+        .then(next);
+  },
+
+  function testTwoLimitTwoSetTimeouts(next) {
+    Protocol.Runtime.evaluate({
+        expression: 'setMaxAsyncTaskStacks(2)//# sourceURL=expr.js'})
+      .then(() => Protocol.Runtime.evaluate({
+        expression: 'twoSetTimeout()//# sourceURL=expr.js', awaitPromise: true
+      }))
+      .then(() => cancelAllAsyncTasks())
+      .then(next);
+  },
+
+  function testThreeLimitTwoSetTimeouts(next) {
+    Protocol.Runtime.evaluate({
+        expression: 'setMaxAsyncTaskStacks(3)//# sourceURL=expr.js'})
+      .then(() => Protocol.Runtime.evaluate({
+        expression: 'twoSetTimeout()//# sourceURL=expr.js', awaitPromise: true
+      }))
+      .then(() => cancelAllAsyncTasks())
+      .then(next);
+  },
+
+  function testTenLimitTwentySetTimeouts(next) {
+    Protocol.Runtime.evaluate({
+        expression: 'setMaxAsyncTaskStacks(10)//# sourceURL=expr.js'})
+      .then(() => Protocol.Runtime.evaluate({
+        expression: 'twentySetTimeout()//# sourceURL=expr.js',
+        awaitPromise: true
+      }))
+      .then(() => cancelAllAsyncTasks())
+      .then(next);
+  }
+]);
+
+function cancelAllAsyncTasks() {
+  return Protocol.Debugger.setAsyncCallStackDepth({ maxDepth: 0 })
+    .then(() => Protocol.Debugger.setAsyncCallStackDepth({ maxDepth: 128 }));
+}