Move implementation of dart:mojo.internal to mojo/public/platform/dart

mojo/PRESUBMIT.py

Index: mojo/PRESUBMIT.py
diff --git a/mojo/PRESUBMIT.py b/mojo/PRESUBMIT.py
index 0a6429502b4f9b1cf9d4569b1b06d94f8dac689a..b261301da4b2dfd690cffaacf7c1d99cb5b542a7 100644
--- a/mojo/PRESUBMIT.py
+++ b/mojo/PRESUBMIT.py
@@ -16,7 +16,8 @@ _PACKAGE_WHITELISTED_EXTERNAL_PATHS = {
     "SDK": ["//build/module_args/mojo.gni",
             "//build/module_args/dart.gni",
             "//testing/gtest",
-            "//third_party/cython"],
+            "//third_party/cython",
+            "//dart/runtime:libdart"],

[jamesr, 2015/10/28 22:17:11]

this allows anything in the SDK to reference this, which isn't what you want.
instead in _FindIllegalAbsolutePathsInBuildFiles check that if
//dart/runtime:libdart is set the build file being checked is in
//mojo/public/platform/dart

[Cutch, 2015/10/28 22:32:09]

Done.

     "services": ["//build/module_args/mojo.gni",
                  "//testing/gtest"],
 }