GN: turn off ccache

infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-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 58 matching lines @@
       "@@@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",
-      "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-GCC-x86_64-Debug-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": {
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]:RECIPE_PACKAGE_REPO[depot_tools]"
     },
     "name": "fetch-gn"
   },
   {
     "cmd": [
       "gn",
       "gen",
       "[CUSTOM_/_B_WORK]/skia/out/Build-Ubuntu-GCC-x86_64-Debug-GN/Debug",
-      "--args=cc=\"gcc\" compiler_prefix=\"/usr/bin/ccache\" cxx=\"g++\" extra_cflags=\"\" extra_ldflags=\"\" is_debug=true"
+      "--args=cc=\"gcc\" cxx=\"g++\" extra_cflags=\"\" extra_ldflags=\"\" is_debug=true"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
     "env": {
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]:RECIPE_PACKAGE_REPO[depot_tools]"
     },
     "name": "gn gen"
   },
   {
     "cmd": [
       "ninja",
@@ skipping 42 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
   }
 ]