Modify Skia recipes to allow running XSAN on Swarming.

scripts/slave/recipes/skia/swarm_perf.expected/Perf-Android-GCC-Nexus7-GPU-Tegra3-Arm7-Release.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[SLAVE_BUILD]/skia/tools/buildbot_spec.py",
       "/path/to/tmp/json",
       "Perf-Android-GCC-Nexus7-GPU-Tegra3-Arm7-Release"
     ],
     "cwd": "[SLAVE_BUILD]/skia",
@@ skipping 401 matching lines @@
       "SKIA_ANDROID_VERBOSE_SETUP": "1",
       "SKIA_OUT": "[SLAVE_BUILD]/out"
     },
     "name": "nanobench"
   },
   {
     "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",
-      "[SWARM_OUT_DIR]/perfdata/Perf-Android-GCC-Nexus7-GPU-Tegra3-Arm7-Release/data",
+      "[CUSTOM_[SWARM_OUT_DIR]]/perfdata/Perf-Android-GCC-Nexus7-GPU-Tegra3-Arm7-Release/data",
       "511"
     ],
     "name": "makedirs perf_dir",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@python.inline@@@@",
       "@@@STEP_LOG_LINE@python.inline@import sys, os@@@",
       "@@@STEP_LOG_LINE@python.inline@path = sys.argv[1]@@@",
       "@@@STEP_LOG_LINE@python.inline@mode = int(sys.argv[2])@@@",
       "@@@STEP_LOG_LINE@python.inline@if not os.path.isdir(path):@@@",
       "@@@STEP_LOG_LINE@python.inline@  if os.path.exists(path):@@@",
       "@@@STEP_LOG_LINE@python.inline@    print \"%s exists but is not a dir\" % path@@@",
       "@@@STEP_LOG_LINE@python.inline@    sys.exit(1)@@@",
       "@@@STEP_LOG_LINE@python.inline@  os.makedirs(path, mode)@@@",
       "@@@STEP_LOG_END@python.inline@@@"
     ]
   },
   {
     "cmd": [
       "[SLAVE_BUILD]/skia/platform_tools/android/bin/adb_pull_if_needed",
       "--verbose",
       "/storage/emulated/legacy/skiabot/skia_perf",
-      "[SWARM_OUT_DIR]/perfdata/Perf-Android-GCC-Nexus7-GPU-Tegra3-Arm7-Release/data"
+      "[CUSTOM_[SWARM_OUT_DIR]]/perfdata/Perf-Android-GCC-Nexus7-GPU-Tegra3-Arm7-Release/data"
     ],
     "env": {
       "ANDROID_HOME": "/b/android-sdk-linux",
       "ANDROID_SDK_ROOT": "/b/android-sdk-linux",
       "BUILDTYPE": "Release",
       "CHROME_HEADLESS": "1",
       "GYP_DEFINES": "skia_arch_type=arm skia_dump_stats=1 skia_warnings_as_errors=0",
       "PATH": "[DEPOT_TOOLS]:%(PATH)s",
       "PYTHONPATH": "[BUILD]/scripts",
       "SKIA_ANDROID_VERBOSE_SETUP": "1",
@@ skipping 96 matching lines @@
       "SKIA_OUT": "[SLAVE_BUILD]/out"
     },
     "name": "kill-server"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]