Revert of Remove catapult_base from telemetry.

tools/telemetry/catapult_base/refactor/annotated_symbol/base_symbol.py

+# Copyright 2015 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.
+
+from catapult_base.refactor import snippet
+
+
+class AnnotatedSymbol(snippet.Symbol):
+  def __init__(self, symbol_type, children):
+    super(AnnotatedSymbol, self).__init__(symbol_type, children)
+    self._modified = False
+
+  @property
+  def modified(self):
+    if self._modified:
+      return True
+    return super(AnnotatedSymbol, self).modified
+
+  def __setattr__(self, name, value):
+    if (hasattr(self.__class__, name) and
+        isinstance(getattr(self.__class__, name), property)):
+      self._modified = True
+    return super(AnnotatedSymbol, self).__setattr__(name, value)
+
+  def Cut(self, child):
+    for i in xrange(len(self._children)):
+      if self._children[i] == child:
+        self._modified = True
+        del self._children[i]
+        break
+    else:
+      raise ValueError('%s is not in %s.' % (child, self))
+
+  def Paste(self, child):
+    self._modified = True
+    self._children.append(child)