Remove snapshot log parsing and option from tools.

BUILD.gn

 # Copyright 2014 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.
 
 import("//build/config/android/config.gni")
 import("//build/config/arm.gni")
 import("//build/config/mips.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 
 if (is_android) {
@@ skipping 491 matching lines @@
   script = "tools/run.py"
 
   outputs = [
     "$target_gen_dir/snapshot.cc",
   ]
 
   args = [
     "./" + rebase_path(get_label_info(":mksnapshot($snapshot_toolchain)",
                                       "root_out_dir") + "/mksnapshot",
                        root_build_dir),
-    "--log-snapshot-positions",
-    "--logfile",
-    rebase_path("$target_gen_dir/snapshot.log", root_build_dir),

[Yang, 2016/04/05 12:37:13]

In src/snapshot/mksnapshot.cc, at the very start of main(), we set two flags for
logging. These should become unnecessary as well.

[Stefano Sanfilippo, 2016/04/05 14:06:09]

Done.

     "--startup_src",
     rebase_path("$target_gen_dir/snapshot.cc", root_build_dir),
   ]
 
   if (v8_random_seed != "0") {
     args += [
       "--random-seed",
       v8_random_seed,
     ]
   }
@@ skipping 1594 matching lines @@
 
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [ "//build/config/compiler:no_chromium_code" ]
   configs += [
     ":internal_config",
     ":libplatform_config",
     ":features",
     ":toolchain",
   ]
 }