tools: implement public api spec

Closes angular#6309

Author: vsavkin

gulpfile.js

@@ -463,7 +463,7 @@ function runKarma(configFile, done) {
 
 gulp.task('test.js', function(done) {
   runSequence('test.unit.tools/ci', 'test.transpiler.unittest', 'test.unit.js/ci',
-              'test.unit.cjs/ci', 'test.typings', sequenceComplete(done));
+              'test.unit.cjs/ci', 'test.typings', 'check-public-api', sequenceComplete(done));
 });
 
 gulp.task('test.dart', function(done) {
@@ -866,6 +866,8 @@ gulp.task('test.unit.cjs/ci', function(done) {
   runJasmineTests(['dist/js/cjs/{angular2,benchpress}/test/**/*_spec.js'], done);
 });
 
+gulp.task('check-public-api',
+          function(done) { runJasmineTests(['dist/tools/public_api_guard/**/*_spec.js'], done); });
 
 gulp.task('test.unit.cjs', ['build/clean.js', 'build.tools'], function(neverDone) {
   var watch = require('./tools/build/watch');

npm-shrinkwrap.clean.json

@@ -5336,6 +5336,9 @@
     "trim-newlines": {
       "version": "1.0.0"
     },
+    "ts-api-guardian": {
+      "version": "0.0.2"
+    },
     "ts2dart": {
       "version": "0.7.19",
       "dependencies": {

npm-shrinkwrap.json

@@ -112,6 +112,7 @@
     "systemjs-builder": "^0.10.3",
     "through2": "^0.6.5",
     "ts2dart": "^0.7.19",
+    "ts-api-guardian": "0.0.2",
     "tsd": "^0.6.5-beta",
     "tslint": "^3.2.1",
     "typescript": "^1.7.3",