Remove a bunch of cruft from //build.

build/gyp_environment.py

Index: build/gyp_environment.py
diff --git a/build/gyp_environment.py b/build/gyp_environment.py
deleted file mode 100644
index fb50645d56fc5adc4276f9ac989a06059c4c4aa3..0000000000000000000000000000000000000000
--- a/build/gyp_environment.py
+++ /dev/null
@@ -1,33 +0,0 @@
-# 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.
-
-"""
-Sets up various automatic gyp environment variables. These are used by
-gyp_chromium and landmines.py which run at different stages of runhooks. To
-make sure settings are consistent between them, all setup should happen here.
-"""
-
-import gyp_helper
-import os
-import sys
-import vs_toolchain
-
-def SetEnvironment():
-  """Sets defaults for GYP_* variables."""
-  gyp_helper.apply_chromium_gyp_env()
-
-  # Default to ninja on linux and windows, but only if no generator has
-  # explicitly been set.
-  # Also default to ninja on mac, but only when not building chrome/ios.
-  # . -f / --format has precedence over the env var, no need to check for it
-  # . set the env var only if it hasn't been set yet
-  # . chromium.gyp_env has been applied to os.environ at this point already
-  if sys.platform.startswith(('linux', 'win', 'freebsd')) and \
-      not os.environ.get('GYP_GENERATORS'):
-    os.environ['GYP_GENERATORS'] = 'ninja'
-  elif sys.platform == 'darwin' and not os.environ.get('GYP_GENERATORS') and \
-      not 'OS=ios' in os.environ.get('GYP_DEFINES', []):
-    os.environ['GYP_GENERATORS'] = 'ninja'
-
-  vs_toolchain.SetEnvironmentAndGetRuntimeDllDirs()