Add explicit support for discovering the GpuProcess to Telemetry's 'Model'.

tools/telemetry/telemetry/timeline/trace_event_importer.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 ''' TraceEventImporter imports TraceEvent-formatted data
 into the provided model.
 This is a port of the trace event importer from
 https://code.google.com/p/trace-viewer/
 '''
 
 import copy
@@ skipping 204 matching lines @@
   def FinalizeImport(self):
     '''Called by the Model after all other importers have imported their
     events.'''
     self._model.UpdateBounds()
 
     # We need to reupdate the bounds in case the minimum start time changes
     self._model.UpdateBounds()
     self._CreateAsyncSlices()
     self._CreateFlowSlices()
     self._SetBrowserProcess()
+    self._SetGpuProcess()
     self._CreateExplicitObjects()
     self._CreateImplicitObjects()
 
   def _CreateAsyncSlices(self):
     if len(self._all_async_events) == 0:
       return
 
     self._all_async_events.sort(
         cmp=lambda x, y: int(x['event']['ts'] - y['event']['ts']))
 
@@ skipping 153 matching lines @@
         if event['ph'] == 'f':
           del flow_id_to_event[event['id']]
         else:
           # Make this event the next start event in this flow.
           flow_id_to_event[event['id']] = flow_event
 
   def _SetBrowserProcess(self):
     for thread in self._model.GetAllThreads():
       if thread.name == 'CrBrowserMain':
         self._model.browser_process = thread.parent
+
+  def _SetGpuProcess(self):
+    for thread in self._model.GetAllThreads():
+      if thread.name == 'CrGpuMain':
+        self._model.gpu_process = thread.parent