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

tools/telemetry/telemetry/timeline/trace_event_importer.py

Index: tools/telemetry/telemetry/timeline/trace_event_importer.py
diff --git a/tools/telemetry/telemetry/timeline/trace_event_importer.py b/tools/telemetry/telemetry/timeline/trace_event_importer.py
index 5b024da3613d0e37a1a0e47eceb7ea2f7deec437..3ed549b7ee4b6d4ff0f6c97f19dd5424a3308279 100644
--- a/tools/telemetry/telemetry/timeline/trace_event_importer.py
+++ b/tools/telemetry/telemetry/timeline/trace_event_importer.py
@@ -222,6 +222,7 @@
     self._CreateAsyncSlices()
     self._CreateFlowSlices()
     self._SetBrowserProcess()
+    self._SetGpuProcess()
     self._CreateExplicitObjects()
     self._CreateImplicitObjects()
 
@@ -395,3 +396,8 @@
     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