Build chromium_gpu_debug_builder target on debug bots.

scripts/slave/recipes/gpu.expected/win_debug_tryserver.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[DEPOT_TOOLS_ROOT]\\gclient.py",
       "config",
       "--spec",
       "cache_dir = None\nsolutions = [{'custom_deps': {'src/third_party/WebKit/LayoutTests': None, 'src/webkit/data/layout_tests/LayoutTests': None}, 'custom_vars': {'googlecode_url': 'svn://svn-mirror.golo.chromium.org/%s', 'nacl_trunk': 'svn://svn-mirror.golo.chromium.org/native_client/trunk', 'sourceforge_url': 'svn://svn-mirror.golo.chromium.org/%(repo)s', 'webkit_trunk': 'svn://svn-mirror.golo.chromium.org/blink/trunk'}, 'deps_file': 'DEPS', 'managed': True, 'name': 'src', 'url': 'svn://svn-mirror.golo.chromium.org/chrome/trunk/src'}, {'custom_deps': {'src/chrome/test/data/firefox2_profile/searchplugins': None, 'src/chrome/test/data/firefox2_searchplugins': None, 'src/chrome/test/data/firefox3_profile/searchplugins': None, 'src/chrome/test/data/firefox3_searchplugins': None, 'src/chrome/test/data/osdd': None, 'src/chrome/test/data/plugin': None, 'src/chrome/test/data/ssl/certs': None, 'src/data/autodiscovery': None, 'src/data/esctf': None, 'src/data/mach_ports': None, 'src/data/memory_test': None, 'src/data/mozilla_js_tests': None, 'src/data/page_cycler': None, 'src/data/selenium_core': None, 'src/data/tab_switching': None, 'src/tools/grit/grit/test/data': None, 'src/webkit/data/bmp_decoder': None, 'src/webkit/data/ico_decoder': None, 'src/webkit/data/test_shell/plugins': None, 'src/webkit/data/xbm_decoder': None}, 'deps_file': 'DEPS', 'managed': True, 'name': 'src-internal', 'url': 'svn://svn-mirror.golo.chromium.org/chrome-internal/trunk/src-internal'}]"
     ],
@@ skipping 98 matching lines @@
       "Debug",
       "--build-dir",
       "[SLAVE_BUILD_ROOT]\\src\\out",
       "--src-dir",
       "[SLAVE_BUILD_ROOT]\\src",
       "--build-tool",
       "ninja",
       "--compiler",
       "goma",
       "--",
-      "chromium_gpu_builder"
+      "chromium_gpu_debug_builder"
     ],
     "name": "compile"
   },
   {
     "always_run": true,
     "cmd": [
       "python",
       "-u",
       "[BUILD_ROOT]\\scripts\\slave\\runtest.py",
       "--target",
@@ skipping 91 matching lines @@
       "--generated-dir",
       "[SLAVE_BUILD_ROOT]\\content_gpu_data\\generated",
       "--gpu-reference-dir",
       "[SLAVE_BUILD_ROOT]\\content_gpu_data\\reference",
       "--gsutil",
       "[BUILD_ROOT]\\scripts\\slave\\gsutil.bat"
     ],
     "name": "archive_test_results"
   }
 ]