WebRTC: Add gyp_script parameter to ios recipe module's run_mb call.

scripts/slave/recipes/webrtc/ios.expected/test_failure.json

 [
   {
     "cmd": [
       "RECIPE_PACKAGE_REPO[build]/scripts/slave/ios/host_info.py",
       "--json-file",
       "/path/to/tmp/json"
     ],
     "name": "host and tools info",
     "~followup_annotations": [
       "@@@STEP_TEXT@<br />OS X 1.2.3, Xcode 6.7.8 (5D342509a)@@@",
@@ skipping 102 matching lines @@
     ],
     "name": "read build config",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"GYP_DEFINES\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"fake gyp define 1\": \"fake value 1\", @@@",
       "@@@STEP_LOG_LINE@json.output@    \"fake gyp define 2\": \"fake value 2\"@@@",
       "@@@STEP_LOG_LINE@json.output@  }, @@@",
       "@@@STEP_LOG_LINE@json.output@  \"compiler\": \"xcodebuild\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"configuration\": \"Debug\", @@@",
+      "@@@STEP_LOG_LINE@json.output@  \"mb_type\": \"gyp\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"sdk\": \"iphonesimulator8.0\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"tests\": [@@@",
       "@@@STEP_LOG_LINE@json.output@    {@@@",
       "@@@STEP_LOG_LINE@json.output@      \"app\": \"fake tests 1\", @@@",
       "@@@STEP_LOG_LINE@json.output@      \"device type\": \"fake device\", @@@",
       "@@@STEP_LOG_LINE@json.output@      \"os\": \"8.0\"@@@",
       "@@@STEP_LOG_LINE@json.output@    }, @@@",
       "@@@STEP_LOG_LINE@json.output@    {@@@",
       "@@@STEP_LOG_LINE@json.output@      \"app\": \"fake tests 2\", @@@",
       "@@@STEP_LOG_LINE@json.output@      \"device type\": \"fake device\", @@@",
       "@@@STEP_LOG_LINE@json.output@      \"os\": \"7.1\"@@@",
       "@@@STEP_LOG_LINE@json.output@    }@@@",
       "@@@STEP_LOG_LINE@json.output@  ], @@@",
       "@@@STEP_LOG_LINE@json.output@  \"xcode version\": \"fake xcode version\"@@@",
       "@@@STEP_LOG_LINE@json.output@}@@@",
       "@@@STEP_LOG_END@json.output@@@"
     ]
   },
   {
     "cmd": [
       "echo",
       "-e",
-      "{\n  \"GYP_DEFINES\": {\n    \"OS\": \"ios\", \n    \"component\": \"static_library\", \n    \"fake gyp define 1\": \"fake value 1\", \n    \"fake gyp define 2\": \"fake value 2\"\n  }, \n  \"additional_compile_targets\": [\n    \"All\"\n  ], \n  \"compiler\": \"xcodebuild\", \n  \"configuration\": \"Debug\", \n  \"env\": {}, \n  \"gn_args\": [], \n  \"mastername\": \"chromium.fake\", \n  \"mb_type\": null, \n  \"sdk\": \"iphonesimulator8.0\", \n  \"tests\": [\n    {\n      \"app\": \"fake tests 1\", \n      \"device type\": \"fake device\", \n      \"id\": \"0\", \n      \"os\": \"8.0\"\n    }, \n    {\n      \"app\": \"fake tests 2\", \n      \"device type\": \"fake device\", \n      \"id\": \"1\", \n      \"os\": \"7.1\"\n    }\n  ], \n  \"triggered bots\": {}, \n  \"use_analyze\": true, \n  \"xcode version\": \"fake xcode version\"\n}"
+      "{\n  \"GYP_DEFINES\": {\n    \"OS\": \"ios\", \n    \"component\": \"static_library\", \n    \"fake gyp define 1\": \"fake value 1\", \n    \"fake gyp define 2\": \"fake value 2\"\n  }, \n  \"additional_compile_targets\": [\n    \"All\"\n  ], \n  \"compiler\": \"xcodebuild\", \n  \"configuration\": \"Debug\", \n  \"env\": {}, \n  \"gn_args\": [], \n  \"mastername\": \"chromium.fake\", \n  \"mb_type\": \"gyp\", \n  \"sdk\": \"iphonesimulator8.0\", \n  \"tests\": [\n    {\n      \"app\": \"fake tests 1\", \n      \"device type\": \"fake device\", \n      \"id\": \"0\", \n      \"os\": \"8.0\"\n    }, \n    {\n      \"app\": \"fake tests 2\", \n      \"device type\": \"fake device\", \n      \"id\": \"1\", \n      \"os\": \"7.1\"\n    }\n  ], \n  \"triggered bots\": {}, \n  \"use_analyze\": true, \n  \"xcode version\": \"fake xcode version\"\n}"
     ],
     "name": "finalize build config"
   },
   {
     "cmd": [
       "RECIPE_PACKAGE_REPO[build]/scripts/slave/ios/find_xcode.py",
       "--json-file",
       "/path/to/tmp/json",
       "--version",
       "fake xcode version"
@@ skipping 107 matching lines @@
       "@@@STEP_LINK@fake URL text@fake URL@@@"
     ]
   },
   {
     "name": "$result",
     "reason": "Failed fake tests 1 (fake device iOS 8.0).",
     "recipe_result": null,
     "status_code": 1
   }
 ]