depot_tools: use package_resource to locate gclient.py

recipe_modules/gclient/example.expected/basic.json

Index: recipe_modules/gclient/example.expected/basic.json
diff --git a/recipe_modules/gclient/example.expected/basic.json b/recipe_modules/gclient/example.expected/basic.json
index 93f74535d7dc53fc092a6a144359970e61d91049..15d9d2f40d7fd6fdda79e56cce51b4cbe48c1ff6 100644
--- a/recipe_modules/gclient/example.expected/basic.json
+++ b/recipe_modules/gclient/example.expected/basic.json
@@ -3,7 +3,7 @@
     "cmd": [
       "python",
       "-u",
-      "[DEPOT_TOOLS]/gclient.py",
+      "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'}]"
@@ -15,7 +15,7 @@
     "cmd": [
       "python",
       "-u",
-      "[DEPOT_TOOLS]/gclient.py",
+      "RECIPE_PACKAGE[depot_tools]/gclient.py",
       "sync",
       "--verbose",
       "--with_branch_heads",
@@ -46,7 +46,7 @@
     "cmd": [
       "python",
       "-u",
-      "[DEPOT_TOOLS]/gclient.py",
+      "RECIPE_PACKAGE[depot_tools]/gclient.py",
       "recurse",
       "git",
       "config",
@@ -60,7 +60,7 @@
     "cmd": [
       "python",
       "-u",
-      "[DEPOT_TOOLS]/gclient.py",
+      "RECIPE_PACKAGE[depot_tools]/gclient.py",
       "recurse",
       "git",
       "config",
@@ -74,7 +74,7 @@
     "cmd": [
       "python",
       "-u",
-      "[DEPOT_TOOLS]/gclient.py",
+      "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'}]"
@@ -86,7 +86,7 @@
     "cmd": [
       "python",
       "-u",
-      "[DEPOT_TOOLS]/gclient.py",
+      "RECIPE_PACKAGE[depot_tools]/gclient.py",
       "sync",
       "--nohooks",
       "--force",
@@ -143,7 +143,7 @@
     "cmd": [
       "python",
       "-u",
-      "[DEPOT_TOOLS]/gclient.py",
+      "RECIPE_PACKAGE[depot_tools]/gclient.py",
       "runhooks"
     ],
     "cwd": "[SLAVE_BUILD]",