[Predator] Move ``FilterStackBuffer`` from stack parser to ``AddFilteredStack`` of stacktrace buffe…

appengine/findit/crash/test/stacktrace_parser_test.py

-# Copyright 2016 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 crash import callstack_filters
-from crash.stacktrace import CallStackBuffer
-from crash.stacktrace import StackFrame
-from crash.stacktrace_parser import StacktraceParser
-from crash.test.stacktrace_test_suite import StacktraceTestSuite
-
-
-class DummyFilter(callstack_filters.CallStackFilter):
-
-  def __call__(self, stack_buffer):  # pragma: no cover
-    return stack_buffer
-
-
-class StacktraceParserTest(StacktraceTestSuite):
-
-  def testFilterInfinityPriorityStackBuffer(self):
-    """Tests ``FilterStackBuffer`` return None for inf priority stack buffer."""
-    stack_buffer = CallStackBuffer(priority=float('inf'))
-    self.assertIsNone(StacktraceParser.FilterStackBuffer(stack_buffer,
-                                                         [DummyFilter()]))
-
-  def testFilterEmptyStackBuffer(self):
-    """Tests ``FilterStackBuffer`` return None for empty stack buffer."""
-    stack_buffer = CallStackBuffer(frame_list=[])
-    self.assertIsNone(StacktraceParser.FilterStackBuffer(stack_buffer,
-                                                         [DummyFilter()]))
-
-  def testFilterAllFrames(self):
-    """Tests ``FilterStackBuffer`` filters all frames and resturn None."""
-    frame_list = [
-        StackFrame(0, 'src/', 'func', 'file0.cc', 'src/file0.cc', [32]),
-        StackFrame(0, 'src/', 'func2', 'file0.cc', 'src/file0.cc', [32])]
-    stack_buffer = CallStackBuffer(0, frame_list=frame_list)
-
-    def _MockFilter(stack_buffer):
-      stack_buffer.frames = None
-      return stack_buffer
-
-    self.assertIsNone(StacktraceParser.FilterStackBuffer(
-        stack_buffer,
-        filters=[_MockFilter]))
-
-  def testFilterSomeFrames(self):
-    """Tests ``FilterStackBuffer`` filters some frames."""
-    frame_list = [
-        StackFrame(0, 'src/', 'func', 'file0.cc', 'src/file0.cc', [32]),
-        StackFrame(0, 'src/', 'func2', 'file0.cc', 'src/file0.cc', [32])]
-    stack_buffer = CallStackBuffer(0, frame_list=frame_list)
-
-    def _MockFilter(stack):
-      stack.frames = stack.frames[:1]
-      return stack
-
-    self._VerifyTwoCallStacksEqual(
-        StacktraceParser.FilterStackBuffer(stack_buffer, filters=[_MockFilter]),
-        CallStackBuffer(stack_buffer.priority, frame_list=frame_list[:1]))