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

appengine/findit/crash/stacktrace_parser.py

Index: appengine/findit/crash/stacktrace_parser.py
diff --git a/appengine/findit/crash/stacktrace_parser.py b/appengine/findit/crash/stacktrace_parser.py
index 0080ce5e774ecd3f55845b4ce08edb5341053b09..d9b7f4720243eb086097e04a76d0b4eaaa24c62b 100644
--- a/appengine/findit/crash/stacktrace_parser.py
+++ b/appengine/findit/crash/stacktrace_parser.py
@@ -10,34 +10,6 @@ from crash.stacktrace import Stacktrace
 
 class StacktraceParser(object):
 
-  @staticmethod
-  def FilterStackBuffer(stack_buffer, filters):
-    """Builds stack buffer to keep all the Callstack inforamtion and metadata.
-
-    Filter stack buffers and cache all the metadata for later use in
-    ``BuildStackTrace``.
-
-    Args:
-      stack_buffer (CallStackBuffer): callstack buffer to be filtered.
-      filters (list): List of Filter objs, each Filter obj is callable and takes
-        stack_buffer as the only parameter.
-
-    Returns:
-      A new ``CallStackBuffer`` instance, None when all the frames of the
-      stack buffer are filtered.
-    """
-    # If the callstack is the initial one (infinte priority) or empty, return
-    # None.
-    if math.isinf(stack_buffer.priority) or not stack_buffer.frames:
-      return None
-
-    for stack_filter in filters:
-      stack_buffer = stack_filter(stack_buffer)
-      if not stack_buffer:
-        return None
-
-    return stack_buffer
-
   def Parse(self, stacktrace_string, deps, signature=None, top_n_frames=None):
     """Parses stacktrace_string into ``Stacktrace`` instance.