Fix HashTable growth strategy to be 2x instead of 4x

tools/dev/gm.py

 #!/usr/bin/env python
 # Copyright 2017 the V8 project authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 """\
 Convenience wrapper for compiling V8 with gn/ninja and running tests.
 Sets up build output directories if they don't exist.
 Produces simulator builds for non-Intel target architectures.
 Uses Goma by default if it is detected (at output directory setup time).
 Expects to be run from the root of a V8 checkout.
@@ skipping 222 matching lines @@
         self.PopulateConfigs(DEFAULT_ARCHES, DEFAULT_MODES, **impact)
 
   def ParseArg(self, argstring):
     if argstring in ("-h", "--help", "help"):
       PrintHelpAndExit()
     arches = []
     modes = []
     targets = []
     actions = []
     tests = []
-    words = argstring.split('.')
+    # Specifying a single unit test looks like "unittests/Foo.Bar".
+    if argstring.startswith("unittests/"):
+      words = [argstring]
+    else:
+      words = argstring.split('.')
     if len(words) == 1:
       word = words[0]
       if word in ACTIONS:
         self.global_actions.add(word)
         return
       if word in TARGETS:
         self.global_targets.add(word)
         return
       maybe_target = GetTestBinary(word)
       if maybe_target is not None:
@@ skipping 50 matching lines @@
   if return_code == 0:
     _Call("notify-send 'Done!' 'V8 compilation finished successfully.'",
           silent=True)
   else:
     _Call("notify-send 'Error!' 'V8 compilation finished with errors.'",
           silent=True)
   return return_code
 
 if __name__ == "__main__":
   sys.exit(Main(sys.argv))