gclient: add depot_tools to PATH

recipe_modules/gclient/example.expected/tryserver.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE[depot_tools]/gclient.py",
       "config",
       "--spec",
       "cache_dir = '[ROOT]/git_cache'\nsolutions = [{'deps_file': '.DEPS.git', 'managed': True, 'name': 'src', 'url': 'https://chromium.googlesource.com/chromium/src.git'}]"
     ],
     "cwd": "[SLAVE_BUILD]",
+    "env": {
+      "PATH": "%(PATH)s:RECIPE_PACKAGE[depot_tools]"
+    },
     "name": "gclient setup"
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE[depot_tools]/gclient.py",
       "sync",
       "--verbose",
       "--with_branch_heads",
       "--nohooks",
       "-j8",
       "--reset",
       "--force",
       "--upstream",
       "--no-nag-max",
       "--delete_unversioned_trees",
       "--revision",
       "src@HEAD",
       "--output-json",
       "/path/to/tmp/json"
     ],
     "cwd": "[SLAVE_BUILD]",
+    "env": {
+      "PATH": "%(PATH)s:RECIPE_PACKAGE[depot_tools]"
+    },
     "name": "gclient sync",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"solutions\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"src/\": {@@@",
       "@@@STEP_LOG_LINE@json.output@      \"revision\": \"f27fede2220bcd326aee3e86ddfd4ebd0fe58cb9\"@@@",
       "@@@STEP_LOG_LINE@json.output@    }@@@",
       "@@@STEP_LOG_LINE@json.output@  }@@@",
       "@@@STEP_LOG_LINE@json.output@}@@@",
       "@@@STEP_LOG_END@json.output@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE[depot_tools]/gclient.py",
       "recurse",
       "git",
       "config",
       "user.name",
       "local_bot"
     ],
     "cwd": "[SLAVE_BUILD]",
+    "env": {
+      "PATH": "%(PATH)s:RECIPE_PACKAGE[depot_tools]"
+    },
     "name": "gclient recurse (git config user.name)"
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE[depot_tools]/gclient.py",
       "recurse",
       "git",
       "config",
       "user.email",
       "local_bot@example.com"
     ],
     "cwd": "[SLAVE_BUILD]",
+    "env": {
+      "PATH": "%(PATH)s:RECIPE_PACKAGE[depot_tools]"
+    },
     "name": "gclient recurse (git config user.email)"
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE[depot_tools]/gclient.py",
       "config",
       "--spec",
       "cache_dir = None\nsolutions = [{'deps_file': 'DEPS', 'managed': True, 'name': 'WebKit', 'safesync_url': 'https://blink-status.appspot.com/lkgr', 'url': 'svn://svn.chromium.org/blink/trunk'}]"
     ],
     "cwd": "[SLAVE_BUILD]/src/third_party",
+    "env": {
+      "PATH": "%(PATH)s:RECIPE_PACKAGE[depot_tools]"
+    },
     "name": "[spec: WebKit] gclient setup"
   },
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/gclient_safe_revert.py",
       ".",
       "[DEPOT_TOOLS]/gclient"
     ],
@@ skipping 10 matching lines @@
       "--force",
       "--verbose",
       "--delete_unversioned_trees",
       "--with_branch_heads",
       "--revision",
       "third_party/WebKit@123",
       "--output-json",
       "/path/to/tmp/json"
     ],
     "cwd": "[SLAVE_BUILD]/src/third_party",
+    "env": {
+      "PATH": "%(PATH)s:RECIPE_PACKAGE[depot_tools]"
+    },
     "name": "[spec: WebKit] gclient sync",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"solutions\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"WebKit/\": {@@@",
       "@@@STEP_LOG_LINE@json.output@      \"revision\": 241198@@@",
       "@@@STEP_LOG_LINE@json.output@    }, @@@",
       "@@@STEP_LOG_LINE@json.output@    \"src/blatley/\": {@@@",
       "@@@STEP_LOG_LINE@json.output@      \"revision\": 248087@@@",
       "@@@STEP_LOG_LINE@json.output@    }@@@",
@@ skipping 28 matching lines @@
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE[depot_tools]/gclient.py",
       "runhooks"
     ],
     "cwd": "[SLAVE_BUILD]",
+    "env": {
+      "PATH": "%(PATH)s:RECIPE_PACKAGE[depot_tools]"
+    },
     "name": "gclient runhooks"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]