gyp: use all processors instead of hard-coded 8

pylib/gyp/input.py

 # Copyright (c) 2012 Google Inc. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 from compiler.ast import Const
 from compiler.ast import Dict
 from compiler.ast import Discard
 from compiler.ast import List
 from compiler.ast import Module
 from compiler.ast import Node
@@ skipping 585 matching lines @@
       parallel_state.pending += 1
       data_in = {}
       data_in['target_build_files'] = data['target_build_files']
       aux_data_in = {}
       global_flags = {
         'path_sections': globals()['path_sections'],
         'non_configuration_keys': globals()['non_configuration_keys'],
         'multiple_toolsets': globals()['multiple_toolsets']}
 
       if not parallel_state.pool:
-        parallel_state.pool = multiprocessing.Pool(8)
+        parallel_state.pool = multiprocessing.Pool(multiprocessing.cpu_count())
       parallel_state.pool.apply_async(
           CallLoadTargetBuildFile,
           args = (global_flags, dependency,
                   data_in, aux_data_in,
                   variables, includes, depth, check, generator_input_info),
           callback = parallel_state.LoadTargetBuildFileCallback)
   except KeyboardInterrupt, e:
     parallel_state.pool.terminate()
     raise e
 
@@ skipping 2234 matching lines @@
     ValidateRunAsInTarget(target, target_dict, build_file)
     ValidateActionsInTarget(target, target_dict, build_file)
 
   # Generators might not expect ints.  Turn them into strs.
   TurnIntIntoStrInDict(data)
 
   # TODO(mark): Return |data| for now because the generator needs a list of
   # build files that came in.  In the future, maybe it should just accept
   # a list, and not the whole data dict.
   return [flat_list, targets, data]