DEPS update to grab fixed package_config.

tools/deps/dartium.deps/DEPS

Index: tools/deps/dartium.deps/DEPS
diff --git a/tools/deps/dartium.deps/DEPS b/tools/deps/dartium.deps/DEPS
index c3e227474649d0cc6ff0077b088f225b22114f49..3869a2095bd6c418555dcb083340984102071b31 100644
--- a/tools/deps/dartium.deps/DEPS
+++ b/tools/deps/dartium.deps/DEPS
@@ -34,7 +34,7 @@ vars.update({
   "metatest_rev": "@e5aa8e4e19fc4188ac2f6d38368a47d8f07c3df1",
   "oauth2_rev": "@1bff41f4d54505c36f2d1a001b83b8b745c452f5",
   "observatory_pub_packages_rev": "@cdc4b3d4c15b9c0c8e7702dff127b440afbb7485",
-  "package_config_tag": "@0.1.3-dev",
+  "package_config_rev": "@1998ff79238169eb288b90b7eb29c2915105b0e4",
   "path_rev": "@b657c0854d1cf41c014986fa9d2321f1173df805",
   "plugin_tag": "@0.1.0",
   "pool_rev": "@22e12aeb16ad0b626900dbe79e4a25391ddfb28c",
@@ -153,7 +153,7 @@ deps.update({
       "https://github.com/dart-lang/path.git" + Var("path_rev"),
   "src/dart/third_party/pkg/package_config":
       "https://github.com/dart-lang/package_config.git" +
-      Var("package_config_tag"),
+      Var("package_config_rev"),
   "src/dart/third_party/pkg/source_span":
       "https://github.com/dart-lang/source_span.git" + Var("source_span_rev"),
   "src/dart/third_party/pkg/stack_trace":