[Cronet] Enforce ARMv7 Cronet doesn't inadvertently use ARM Neon instructions

tools/mb/mb_config.pyl

Index: tools/mb/mb_config.pyl
diff --git a/tools/mb/mb_config.pyl b/tools/mb/mb_config.pyl
index 0a9eaeffa076b9578245c312085f2e56fb9745da..c4db203a9511d57598ae3aca8f0e1fdb662d7e81 100644
--- a/tools/mb/mb_config.pyl
+++ b/tools/mb/mb_config.pyl
@@ -934,11 +934,11 @@
 
     'android_cronet_data_reduction_proxy_gn_release_bot_minimal_symbols': [
       'android', 'cronet', 'data_reduction_proxy', 'gn',
-      'release_bot_minimal_symbols', 'arm'
+      'release_bot_minimal_symbols', 'arm_no_neon'
     ],
 
     'android_cronet_gn_debug_static_bot': [
-      'android', 'cronet', 'gn', 'debug_static_bot', 'arm'
+      'android', 'cronet', 'gn', 'debug_static_bot', 'arm_no_neon'
     ],
 
     'android_cronet_gn_debug_static_bot_arm64': [
@@ -950,7 +950,7 @@
     ],
 
     'android_cronet_gn_release_bot_minimal_symbols': [
-      'android', 'cronet', 'gn', 'release_bot_minimal_symbols', 'arm'
+      'android', 'cronet', 'gn', 'release_bot_minimal_symbols', 'arm_no_neon'
     ],
 
     'android_cronet_gn_release_bot_minimal_symbols_arm64': [
@@ -962,8 +962,8 @@
     ],
 
     'android_cronet_gn_release_bot_minimal_symbols_clang_asan': [
-      'android', 'cronet', 'gn', 'release_bot_minimal_symbols', 'arm', 'clang',
-      'asan'
+      'android', 'cronet', 'gn', 'release_bot_minimal_symbols', 'arm_no_neon',
+      'clang', 'asan'
     ],
 
     'android_cronet_gn_release_bot_minimal_symbols_mipsel': [
@@ -1896,6 +1896,11 @@
       'gyp_defines': 'target_arch=arm',
     },
 
+    'arm_no_neon': {
+      'gn_args': 'target_cpu="arm" arm_use_neon=false',

[jbudorick, 2016/07/19 18:49:16]

I don't think this should duplicate the arm parameters. You might be able to do
something like this, though:

  'arm_no_neon': {
    'mixins': ['arm'],
    'gn_args': 'arm_use_neon=false',
    'gyp_defines': 'arm_neon=0',
  },

That may not work, or it may not be recommended style, so you could also do

  'no_neon': {
    'gn_args': 'arm_use_neon=false',
    'gyp_defines': 'arm_neon=0',
  },

  'arm_no_neon': {
    'mixins': ['arm', 'no_neon'],
  },

[pauljensen, 2016/07/20 15:04:38]

Done.

+      'gyp_defines': 'target_arch=arm arm_neon=0',
+    },
+
     'arm64': {
       'gn_args': 'target_cpu="arm64"',
       'gyp_defines': 'target_arch=arm64',