Reland [telemetry] Timeline model cleanups

tools/telemetry/telemetry/core/timeline/event.py

Index: tools/telemetry/telemetry/core/timeline/event.py
diff --git a/tools/telemetry/telemetry/core/timeline/event.py b/tools/telemetry/telemetry/core/timeline/event.py
index 6b8d8db9ee8dd7a58b91871991053dd6ca5889b4..8b9db4cef72e082401be71fb0bf9ab3f32b591b9 100644
--- a/tools/telemetry/telemetry/core/timeline/event.py
+++ b/tools/telemetry/telemetry/core/timeline/event.py
@@ -4,25 +4,17 @@
 
 class TimelineEvent(object):
   """Represents a timeline event."""
-  def __init__(self, name, start, duration, args=None, parent=None):
+  def __init__(self, category, name, start, duration, args=None):
+    self.category = category
     self.name = name
     self.start = start
     self.duration = duration
-    self.children = []
-    self.parent = parent
     self.args = args
 
   @property
   def end(self):
     return self.start + self.duration
 
-  @property
-  def self_time(self):
-    """Time spent in this function less any time spent in child events."""
-    child_total = sum(
-      [e.duration for e in self.children])
-    return self.duration - child_total
-
   def __repr__(self):
     if self.args:
       args_str = ', ' + repr(self.args)
@@ -34,39 +26,3 @@ class TimelineEvent(object):
       self.start,
       self.duration,
       args_str)
-
-  @staticmethod
-  def _GetAllChildrenRecursive(events, item):
-    events.append(item)
-    for child in item.children:
-      TimelineEvent._GetAllChildrenRecursive(events, child)
-
-  def GetAllChildrenRecursive(self, include_self=False):
-    events = []
-    TimelineEvent._GetAllChildrenRecursive(events, self)
-    if not include_self:
-      del events[0]
-    return events
-
-  def ShiftTimestampsForward(self, delta_time):
-    """ Shifts start time of event by delta_time and also
-    recursively shifts child events.
-    """
-    for event in self.children:
-      event.ShiftTimestampsForward(delta_time)
-    self.start += delta_time
-
-  def UpdateBounds(self):
-    """ Updates the start time to be the minimum start time of all
-    child events and the end time to be the maximum end time of all
-    child events.
-    """
-    if not len(self.children):
-      return
-
-    for event in self.children:
-      event.UpdateBounds()
-
-    self.start = min(self.children, key=lambda e: e.start).start
-    end_timestamp = max(self.children, key=lambda e: e.end).end
-    self.duration = end_timestamp - self.start