Add and use a clang_linux asset.

infra/bots/recipes/swarm_compile.expected/Build-Mac-Clang-x86_64-Release-GN.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "\nimport sys, os\npath = sys.argv[1]\nmode = int(sys.argv[2])\nif not os.path.isdir(path):\n  if os.path.exists(path):\n    print \"%s exists but is not a dir\" % path\n    sys.exit(1)\n  os.makedirs(path, mode)\n",
       "[CUSTOM_/_B_WORK]",
       "511"
     ],
     "name": "makedirs checkout_path",
@@ skipping 14 matching lines @@
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[depot_tools]/gclient.py",
       "config",
       "--spec",
       "cache_dir = '[CUSTOM_/_B_CACHE]'\nsolutions = [{'deps_file': 'DEPS', 'managed': False, 'name': 'skia', 'url': 'https://skia.googlesource.com/skia.git'}]\ntarget_os = ['llvm']"
     ],
     "cwd": "[CUSTOM_/_B_WORK]",
     "env": {
-      "BUILDTYPE": "Debug",
+      "BUILDTYPE": "Release",
       "CHROME_HEADLESS": "1",
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]",
-      "SKIA_OUT": "[CUSTOM_/_B_WORK]/skia/out/Build-Ubuntu-Clang-x86_64-Debug-GN"
+      "SKIA_OUT": "[CUSTOM_/_B_WORK]/skia/out/Build-Mac-Clang-x86_64-Release-GN"
     },
     "name": "gclient setup"
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[depot_tools]/gclient.py",
       "sync",
       "--nohooks",
       "--force",
       "--verbose",
       "--delete_unversioned_trees",
       "--revision",
       "skia@abc123",
       "--output-json",
       "/path/to/tmp/json"
     ],
     "cwd": "[CUSTOM_/_B_WORK]",
     "env": {
-      "BUILDTYPE": "Debug",
+      "BUILDTYPE": "Release",
       "CHROME_HEADLESS": "1",
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]:RECIPE_PACKAGE_REPO[depot_tools]",
-      "SKIA_OUT": "[CUSTOM_/_B_WORK]/skia/out/Build-Ubuntu-Clang-x86_64-Debug-GN"
+      "SKIA_OUT": "[CUSTOM_/_B_WORK]/skia/out/Build-Mac-Clang-x86_64-Release-GN"
     },
     "name": "gclient sync",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"solutions\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"skia/\": {@@@",
       "@@@STEP_LOG_LINE@json.output@      \"revision\": 164710@@@",
       "@@@STEP_LOG_LINE@json.output@    }@@@",
       "@@@STEP_LOG_LINE@json.output@  }@@@",
       "@@@STEP_LOG_LINE@json.output@}@@@",
       "@@@STEP_LOG_END@json.output@@@",
       "@@@SET_BUILD_PROPERTY@got_revision@164710@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "import json\nimport subprocess\nimport sys\n\nccache = None\ntry:\n  ccache = subprocess.check_output(['which', 'ccache']).rstrip()\nexcept:\n  pass\nprint json.dumps({'ccache': ccache})\n"
     ],
     "env": {
-      "BUILDTYPE": "Debug",
+      "BUILDTYPE": "Release",
       "CHROME_HEADLESS": "1",
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]:RECIPE_PACKAGE_REPO[depot_tools]",
-      "SKIA_OUT": "[CUSTOM_/_B_WORK]/skia/out/Build-Ubuntu-Clang-x86_64-Debug-GN"
+      "SKIA_OUT": "[CUSTOM_/_B_WORK]/skia/out/Build-Mac-Clang-x86_64-Release-GN"
     },
     "name": "has ccache?",
     "stdout": "/path/to/tmp/json",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"ccache\": \"/usr/bin/ccache\"@@@",
       "@@@STEP_LOG_LINE@json.output@}@@@",
       "@@@STEP_LOG_END@json.output@@@",
       "@@@STEP_LOG_LINE@python.inline@import json@@@",
       "@@@STEP_LOG_LINE@python.inline@import subprocess@@@",
       "@@@STEP_LOG_LINE@python.inline@import sys@@@",
       "@@@STEP_LOG_LINE@python.inline@@@@",
       "@@@STEP_LOG_LINE@python.inline@ccache = None@@@",
       "@@@STEP_LOG_LINE@python.inline@try:@@@",
       "@@@STEP_LOG_LINE@python.inline@  ccache = subprocess.check_output(['which', 'ccache']).rstrip()@@@",
       "@@@STEP_LOG_LINE@python.inline@except:@@@",
       "@@@STEP_LOG_LINE@python.inline@  pass@@@",
       "@@@STEP_LOG_LINE@python.inline@print json.dumps({'ccache': ccache})@@@",
       "@@@STEP_LOG_END@python.inline@@@"
     ]
   },
   {
     "cmd": [
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
     "env": {
-      "BUILDTYPE": "Debug",
+      "BUILDTYPE": "Release",
       "CC": "/usr/bin/clang",
       "CHROME_HEADLESS": "1",
       "CXX": "/usr/bin/clang++",
       "GYP_DEFINES": "skia_arch_type=x86_64 skia_clang_build=1 skia_warnings_as_errors=1",
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]:RECIPE_PACKAGE_REPO[depot_tools]",
-      "SKIA_OUT": "[CUSTOM_/_B_WORK]/skia/out/Build-Ubuntu-Clang-x86_64-Debug-GN"
+      "SKIA_OUT": "[CUSTOM_/_B_WORK]/skia/out/Build-Mac-Clang-x86_64-Release-GN"
     },
     "name": "fetch-gn"
   },
   {
     "cmd": [
       "gn",
       "gen",
-      "[CUSTOM_/_B_WORK]/skia/out/Build-Ubuntu-Clang-x86_64-Debug-GN/Debug",
-      "--args=cc=\"clang\" cxx=\"clang++\" is_debug=true extra_cflags=\"-Qunused-arguments\" compiler_prefix=\"/usr/bin/ccache\""
+      "[CUSTOM_/_B_WORK]/skia/out/Build-Mac-Clang-x86_64-Release-GN/Release",
+      "--args=cc=\"clang\" compiler_prefix=\"/usr/bin/ccache\" cxx=\"clang++\" extra_cflags=\"-Qunused-arguments\" is_debug=false"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
     "env": {
-      "BUILDTYPE": "Debug",
+      "BUILDTYPE": "Release",
       "CC": "/usr/bin/clang",
       "CHROME_HEADLESS": "1",
       "CXX": "/usr/bin/clang++",
       "GYP_DEFINES": "skia_arch_type=x86_64 skia_clang_build=1 skia_warnings_as_errors=1",
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]:RECIPE_PACKAGE_REPO[depot_tools]",
-      "SKIA_OUT": "[CUSTOM_/_B_WORK]/skia/out/Build-Ubuntu-Clang-x86_64-Debug-GN"
+      "SKIA_OUT": "[CUSTOM_/_B_WORK]/skia/out/Build-Mac-Clang-x86_64-Release-GN"
     },
     "name": "gn gen"
   },
   {
     "cmd": [
       "ninja",
       "-C",
-      "[CUSTOM_/_B_WORK]/skia/out/Build-Ubuntu-Clang-x86_64-Debug-GN/Debug"
+      "[CUSTOM_/_B_WORK]/skia/out/Build-Mac-Clang-x86_64-Release-GN/Release"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
     "env": {
-      "BUILDTYPE": "Debug",
+      "BUILDTYPE": "Release",
       "CC": "/usr/bin/clang",
       "CHROME_HEADLESS": "1",
       "CXX": "/usr/bin/clang++",
       "GYP_DEFINES": "skia_arch_type=x86_64 skia_clang_build=1 skia_warnings_as_errors=1",
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]:RECIPE_PACKAGE_REPO[depot_tools]",
-      "SKIA_OUT": "[CUSTOM_/_B_WORK]/skia/out/Build-Ubuntu-Clang-x86_64-Debug-GN"
+      "SKIA_OUT": "[CUSTOM_/_B_WORK]/skia/out/Build-Mac-Clang-x86_64-Release-GN"
     },
     "name": "ninja"
   },
   {
     "cmd": [
       "python",
       "-u",
       "import errno\nimport glob\nimport os\nimport shutil\nimport sys\n\nsrc = sys.argv[1]\ndst = sys.argv[2]\nbuild_products_whitelist = ['dm', 'dm.exe', 'get_images_from_skps', 'get_images_from_skps.exe', 'nanobench', 'nanobench.exe', '*.so', '*.dll', '*.dylib', 'skia_launcher', 'lib/*.so', 'iOSShell.app', 'iOSShell.ipa', 'visualbench', 'visualbench.exe', 'vulkan-1.dll']\n\ntry:\n  os.makedirs(dst)\nexcept OSError as e:\n  if e.errno != errno.EEXIST:\n    raise\n\nfor pattern in build_products_whitelist:\n  path = os.path.join(src, pattern)\n  for f in glob.glob(path):\n    dst_path = os.path.join(dst, os.path.relpath(f, src))\n    if not os.path.isdir(os.path.dirname(dst_path)):\n      os.makedirs(os.path.dirname(dst_path))\n    print 'Copying build product %s to %s' % (f, dst_path)\n    shutil.move(f, dst_path)\n",
-      "[CUSTOM_/_B_WORK]/skia/out/Build-Ubuntu-Clang-x86_64-Debug-GN/Debug",
-      "[CUSTOM_[SWARM_OUT_DIR]]/out/Debug"
+      "[CUSTOM_/_B_WORK]/skia/out/Build-Mac-Clang-x86_64-Release-GN/Release",
+      "[CUSTOM_[SWARM_OUT_DIR]]/out/Release"
     ],
     "name": "copy build products",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@python.inline@import errno@@@",
       "@@@STEP_LOG_LINE@python.inline@import glob@@@",
       "@@@STEP_LOG_LINE@python.inline@import os@@@",
       "@@@STEP_LOG_LINE@python.inline@import shutil@@@",
       "@@@STEP_LOG_LINE@python.inline@import sys@@@",
       "@@@STEP_LOG_LINE@python.inline@@@@",
       "@@@STEP_LOG_LINE@python.inline@src = sys.argv[1]@@@",
@@ skipping 16 matching lines @@
       "@@@STEP_LOG_LINE@python.inline@    shutil.move(f, dst_path)@@@",
       "@@@STEP_LOG_END@python.inline@@@"
     ]
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]