Reland "Skia: Maintain a checkout on swarming (compile) bots"

scripts/slave/recipes/skia/swarm_perf.expected/Test-Ubuntu-GCC-ShuttleA-GPU-GTX550Ti-x86_64-Release-Valgrind.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[SLAVE_BUILD]/skia/tools/buildbot_spec.py",
       "/path/to/tmp/json",
       "Test-Ubuntu-GCC-ShuttleA-GPU-GTX550Ti-x86_64-Release-Valgrind"
     ],
     "cwd": "[SLAVE_BUILD]/skia",
@@ skipping 71 matching lines @@
       "[SLAVE_BUILD]/skps",
       "--images",
       "[SLAVE_BUILD]/images/dm",
       "--nocpu",
       "--dummy-flags"
     ],
     "env": {
       "BUILDTYPE": "Release",
       "CHROME_HEADLESS": "1",
       "GYP_DEFINES": "skia_arch_type=x86_64 skia_release_optimization_level=1 skia_warnings_as_errors=0",
-      "PATH": "[SLAVE_BUILD]/depot_tools:%(PATH)s",
+      "PATH": "[DEPOT_TOOLS]:%(PATH)s",
+      "PYTHONPATH": "[BUILD]/scripts",
       "SKIA_OUT": "[SLAVE_BUILD]/out"
     },
     "name": "nanobench"
   },
   {
     "cmd": [
       "valgrind",
       "--gen-suppressions=all",
       "--leak-check=full",
       "--track-origins=yes",
@@ skipping 10 matching lines @@
       "[SLAVE_BUILD]/images/dm",
       "--nocpu",
       "--dummy-flags",
       "--abandonGpuContext",
       "--nocpu"
     ],
     "env": {
       "BUILDTYPE": "Release",
       "CHROME_HEADLESS": "1",
       "GYP_DEFINES": "skia_arch_type=x86_64 skia_release_optimization_level=1 skia_warnings_as_errors=0",
-      "PATH": "[SLAVE_BUILD]/depot_tools:%(PATH)s",
+      "PATH": "[DEPOT_TOOLS]:%(PATH)s",
+      "PYTHONPATH": "[BUILD]/scripts",
       "SKIA_OUT": "[SLAVE_BUILD]/out"
     },
     "name": "nanobench --abandonGpuContext"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]