Remove checkout of NSS and sqlite from DEPS, remove support files.

DEPS

Index: DEPS
diff --git a/DEPS b/DEPS
index e88433d4b1a21ab9c3c2d8237f58514af8b7ba31..151acad0db73b98790b02b9d3f4306ab4c6abfae 100644
--- a/DEPS
+++ b/DEPS
@@ -75,8 +75,6 @@ vars = {
   "metatest_rev": "@e5aa8e4e19fc4188ac2f6d38368a47d8f07c3df1",
   "mime_rev": "@75890811d4af5af080351ba8a2853ad4c8df98dd",
   "mustache4dart_rev" : "@5724cfd85151e5b6b53ddcd3380daf188fe47f92",
-  "net_nss_rev": "@f81948e9a402db94287a43bb34a07ee0daf56cb5",
-  "nss_rev": "@87b96db4268293187d7cf741907a6d5d1d8080e0",
   "oauth2_rev": "@1bff41f4d54505c36f2d1a001b83b8b745c452f5",
   "observe_rev": "@eee2b8ec34236fa46982575fbccff84f61202ac6",
   "observatory_pub_packages_rev": "@cdc4b3d4c15b9c0c8e7702dff127b440afbb7485",
@@ -95,7 +93,6 @@ vars = {
   "shelf_tag": "@0.6.2+1",
   "smoke_rev" : "@f3361191cc2a85ebc1e4d4c33aec672d7915aba9",
   "source_maps_tag": "@0.10.1",
-  "sqlite_rev": "@38811b79f42801662adc0458a25270ab690a6b81",
   "shelf_static_tag": "@0.2.3+1",
   "shelf_web_socket_tag": "@0.0.1+4",
   "source_map_stack_trace_tag": "@1.0.4",
@@ -130,21 +127,10 @@ deps = {
   Var("dart_root") + "/tests/co19/src":
       (Var("github_mirror") % "co19") + Var("co19_rev"),
 
-  Var("dart_root") + "/third_party/nss":
-      Var("chromium_git") + "/chromium/deps/nss.git" + Var("nss_rev"),
-
-  Var("dart_root") + "/third_party/sqlite":
-      Var("chromium_git") + "/chromium/src/third_party/sqlite.git" +
-      Var("sqlite_rev"),
-
   Var("dart_root") + "/third_party/zlib":
       Var("chromium_git") + "/chromium/src/third_party/zlib.git" +
       Var("zlib_rev"),
 
-  Var("dart_root") + "/third_party/net_nss":
-      Var("chromium_git") + "/chromium/src/net/third_party/nss.git" +
-      Var("net_nss_rev"),
-
   Var("dart_root") + "/third_party/boringssl/src":
       "https://boringssl.googlesource.com/boringssl.git" +
       Var("boringssl_rev"),