Recipe changes to move webview perf bots to the android/perf recipe

scripts/slave/recipe_modules/chromium_android/chromium_config.py

 # Copyright 2013 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.
 
 from recipe_engine.config_types import Path
 from recipe_engine import config as recipe_config
 
 import DEPS
 CONFIG_CTX = DEPS['chromium'].CONFIG_CTX
 
@@ skipping 174 matching lines @@
 
 # TODO(zty): figure out what perf builder really wants and use that instead.
 # e.g. official
 @CONFIG_CTX(includes=['main_builder'])
 def perf(c):
   gyp_defs = c.gyp_env.GYP_DEFINES
   gyp_defs['branding'] = 'Chrome'
   gyp_defs['buildtype'] = 'Official'
 
 @CONFIG_CTX(includes=['main_builder'])
-def webview_perf(c):
-  gyp_defs = c.gyp_env.GYP_DEFINES
-
-@CONFIG_CTX(includes=['main_builder'])
 def cast_builder(c):
   c.gyp_env.GYP_DEFINES['chromecast'] = 1
 
 @CONFIG_CTX()
 def errorprone(c):
   c.gyp_env.GYP_DEFINES['enable_errorprone'] = 1