Roll recipe dependencies (nontrivial).

scripts/slave/recipes/client.drmemory.recipe_autogen.expected/win8_cr_builder_clobber.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]\\scripts\\slave\\kill_processes.py"
     ],
     "name": "taskkill"
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[depot_tools::bot_update]\\resources\\bot_update.py",
       "--spec",
       "cache_dir = '[GIT_CACHE]'\nsolutions = [{'custom_deps': {'src/third_party/WebKit/LayoutTests': None}, 'custom_vars': {'googlecode_url': 'http://%s.googlecode.com/svn', 'llvm_url': 'http://llvm.org/svn/llvm-project', 'nacl_trunk': 'http://src.chromium.org/native_client/trunk', 'sourceforge_url': 'https://svn.code.sf.net/p/%(repo)s/code', 'webkit_trunk': 'http://src.chromium.org/blink/trunk'}, 'deps_file': '.DEPS.git', 'managed': True, 'name': 'src', 'url': 'https://chromium.googlesource.com/chromium/src.git'}]",
       "--patch_root",
       "src",
       "--revision_mapping_file",
       "{\"src\": \"got_revision\", \"src/third_party/WebKit\": \"got_webkit_revision\", \"src/tools/swarming_client\": \"got_swarming_client_revision\", \"src/v8\": \"got_v8_revision\"}",
       "--git-cache-dir",
       "[GIT_CACHE]",
       "--output_json",
       "/path/to/tmp/json",
       "--revision",
       "src@123456789abcdef",
       "--output_manifest"
     ],
     "env": {
-      "PATH": "%(PATH)s;RECIPE_PACKAGE_REPO[depot_tools]"
+      "PATH": "RECIPE_PACKAGE_REPO[depot_tools];%(PATH)s"
     },
     "name": "bot_update",
     "~followup_annotations": [
       "@@@STEP_TEXT@Some step text@@@",
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"did_run\": true, @@@",
       "@@@STEP_LOG_LINE@json.output@  \"fixed_revisions\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"src\": \"123456789abcdef\"@@@",
       "@@@STEP_LOG_LINE@json.output@  }, @@@",
       "@@@STEP_LOG_LINE@json.output@  \"manifest\": {@@@",
@@ skipping 93 matching lines @@
       "chromium_builder_dbg_drmemory_win"
     ],
     "name": "compile"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]