Upgrade dartdoc to v0.12.0.

DEPS

Index: DEPS
diff --git a/DEPS b/DEPS
index a8ee25a216efd60035c92d692d181f30dc61da19..5a3618b8f671862ad188c55e674edc9150324d30 100644
--- a/DEPS
+++ b/DEPS
@@ -62,7 +62,7 @@ vars = {
   "dart2js_info_tag" : "@0.5.4+2",
   "dart_services_rev" : "@7aea2574e6f3924bf409a80afb8ad52aa2be4f97",
   "dart_style_tag": "@1.0.6",
-  "dartdoc_tag" : "@v0.9.14-dev",
+  "dartdoc_tag" : "@v0.12.0",
   "fixnum_tag": "@0.10.5",
   "func_tag": "@1.0.0",
   "glob_tag": "@1.1.3",
@@ -83,7 +83,7 @@ vars = {
   "matcher_tag": "@0.12.0+2",
   "metatest_tag": "@0.2.2+3",
   "mime_rev": "@75890811d4af5af080351ba8a2853ad4c8df98dd",
-  "mustache4dart_tag" : "@v1.0.10",
+  "mustache4dart_tag" : "@1d2c49a6b0840132f880880af4bb2b1f519c6f66",

[devoncarew, 2017/06/02 21:08:56]

Is there a published version tag that would work for us?

   "oauth2_tag": "@1.0.2",
   "observable_tag": "@0.17.0",
   "observatory_pub_packages_rev": "@26aad88f1c1915d39bbcbff3cad589e2402fdcf1",
@@ -98,6 +98,7 @@ vars = {
   "pub_rev": "@a8781274e3a38c34a49d4c5bffb98557c6022a75",
   "pub_semver_tag": "@1.3.2",
   "quiver_tag": "@0.22.0",
+  "quiver_hashcode_tag": "@1.0.0",
   "resource_rev":"@a49101ba2deb29c728acba6fb86000a8f730f4b1",
   "root_certificates_rev": "@a4c7c6f23a664a37bc1b6f15a819e3f2a292791a",
   "scheduled_test_tag": "@0.12.11",
@@ -116,6 +117,7 @@ vars = {
   "sunflower_rev": "@879b704933413414679396b129f5dfa96f7a0b1e",
   "test_reflective_loader_tag": "@0.1.0",
   "test_tag": "@0.12.18+1",
+  "tuple_tag": "@v1.0.1",
   "typed_data_tag": "@1.1.3",
   "usage_tag": "@v3.0.0+1",
   "utf_tag": "@0.9.0+3",
@@ -287,6 +289,10 @@ deps = {
       Var("chromium_git")
       + "/external/github.com/google/quiver-dart.git"
       + Var("quiver_tag"),
+  Var("dart_root") + "/third_party/pkg/quiver_hashcode":
+      Var("chromium_git")
+      + "/external/github.com/QuiverDart/quiver_hashcode"
+      + Var("quiver_hashcode_tag"),
   Var("dart_root") + "/third_party/pkg/resource":
       (Var("github_mirror") % "resource") + Var("resource_rev"),
   Var("dart_root") + "/third_party/pkg/scheduled_test":
@@ -326,6 +332,10 @@ deps = {
   Var("dart_root") + "/third_party/pkg/test_reflective_loader":
       (Var("github_mirror") % "test_reflective_loader") +
       Var("test_reflective_loader_tag"),
+  Var("dart_root") + "/third_party/pkg/tuple":
+      Var("chromium_git")
+      + "/external/github.com/kseo/tuple.git"
+      + Var("tuple_tag"),
   Var("dart_root") + "/third_party/pkg/typed_data":
       (Var("github_mirror") % "typed_data") + Var("typed_data_tag"),
   Var("dart_root") + "/third_party/pkg/usage":