Update InspectorBackend.TakeJSHeapSnapshot to make it work with the new HeapProfiler behavior

tools/telemetry/telemetry/core/backends/chrome/inspector_backend.py

Index: tools/telemetry/telemetry/core/backends/chrome/inspector_backend.py
diff --git a/tools/telemetry/telemetry/core/backends/chrome/inspector_backend.py b/tools/telemetry/telemetry/core/backends/chrome/inspector_backend.py
index 1e64311f10008f1763d2c1f4d84c939bfaa0055b..d68c60a2c13b41826c49d8e4c9f6e3deec05171a 100644
--- a/tools/telemetry/telemetry/core/backends/chrome/inspector_backend.py
+++ b/tools/telemetry/telemetry/core/backends/chrome/inspector_backend.py
@@ -322,15 +322,10 @@ class InspectorBackend(object):
     self._page.CollectGarbage()
 
   def TakeJSHeapSnapshot(self, timeout=120):
-    # This is a hack to make the nested function be able to modify the
-    # variables.
-    snapshot_uid = [0]
     snapshot = []
 
     def OnNotification(res):
-      if res['method'] == 'HeapProfiler.addProfileHeader':
-        snapshot_uid[0] = res['params']['header']['uid']
-      elif res['method'] == 'HeapProfiler.addHeapSnapshotChunk':
+      if res['method'] == 'HeapProfiler.addHeapSnapshotChunk':
         snapshot.append(res['params']['chunk'])
 
     def OnClose():
@@ -340,10 +335,7 @@ class InspectorBackend(object):
 
     self.SyncRequest({'method': 'Page.getResourceTree'}, timeout)
     self.SyncRequest({'method': 'Debugger.enable'}, timeout)
-    self.SyncRequest({'method': 'HeapProfiler.clearProfiles'}, timeout)
     self.SyncRequest({'method': 'HeapProfiler.takeHeapSnapshot'}, timeout)
-    self.SyncRequest({'method': 'HeapProfiler.getHeapSnapshot',
-                      'params': {'uid': snapshot_uid[0]}}, timeout)
     snapshot = ''.join(snapshot)
 
     self.UnregisterDomain('HeapProfiler')