Testing support for FF and Safari

Also travis support for testing FF.  See:

https://travis-ci.org/dart-lang/sdk/builds/159331789

On FF 48, 1965 out of 1979 tests are passing.  Run locally:
DDC_BROWSERS=Firefox npm test

On Safari 10 (tech preview), it fails immediately due to a static method named "caller".  We disallow it as a field, but not a method right now.  If I hack that out, 1972 out of 1979 tests appear to pass.

Run locally by installing tech preview and running:
DDC_BROWSERS=Safari SAFARI_BIN=/Applications/Safari\ Technology\ Preview.app/Contents/MacOS/Safari\ Technology\ Preview npm test
R=jmesserly@google.com, rnystrom@google.com

Review URL: https://codereview.chromium.org/2334763002 .

.travis.yml

@@ -9,6 +9,8 @@ cache:
     - $HOME/.nvm
     - $HOME/.pub-cache/hosted
     - pkg/dev_compiler/node_modules
+addons:
+  firefox: latest
 before_install:
   # g++4.8.1 setup
   - if [ "$CXX" == "g++" ]; then sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test; fi
@@ -58,6 +60,7 @@ script:
   - if [[ "$TEST" == node ]]; then ./tool/node_test.sh ; fi
 env:
   - ANALYZER=master
+  - ANALYZER=master DDC_BROWSERS=Firefox
   - ANALYZER=master CXX=g++
   - ANALYZER=master CXX=clang++
   - TEST=coverage
@@ -65,6 +68,7 @@ env:
 matrix:
   allow_failures:
     - env: TEST=node
+    - env: ANALYZER=master DDC_BROWSERS=Firefox
     - env: ANALYZER=master CXX=clang++
 notifications:
   email:

pkg/dev_compiler/karma.conf.js

@@ -89,5 +89,9 @@ module.exports = function(config) {
     configuration.client.captureConsole = true;
   }
 
+  if (process.env.DDC_BROWSERS) {
+    configuration.browsers = process.env.DDC_BROWSERS.split(':');
+  }
+
   config.set(configuration);
 };

pkg/dev_compiler/lib/js/amd/dart_sdk.js

@@ -1021,6 +1021,7 @@ define([], function() {
     if (!jsType) return;
     let extProto = dartExtType.prototype;
     let jsProto = jsType.prototype;
+    if (!jsProto) return;
     jsProto[dart._extensionType] = dartExtType;
     dart._installProperties(jsProto, extProto);
     let originalSigFn = dart.getOwnPropertyDescriptor(dartExtType, dart._methodSig).get;
@@ -1761,7 +1762,7 @@ define([], function() {
   };
   dart.nullSafe = function(obj, ...callbacks) {
     if (obj == null) return obj;
-    for (const callback of callbacks) {
+    for (let callback of callbacks) {
       obj = callback(obj);
       if (obj == null) break;
     }

pkg/dev_compiler/lib/js/common/dart_sdk.js

@@ -1021,6 +1021,7 @@
     if (!jsType) return;
     let extProto = dartExtType.prototype;
     let jsProto = jsType.prototype;
+    if (!jsProto) return;
     jsProto[dart._extensionType] = dartExtType;
     dart._installProperties(jsProto, extProto);
     let originalSigFn = dart.getOwnPropertyDescriptor(dartExtType, dart._methodSig).get;
@@ -1761,7 +1762,7 @@
   };
   dart.nullSafe = function(obj, ...callbacks) {
     if (obj == null) return obj;
-    for (const callback of callbacks) {
+    for (let callback of callbacks) {
       obj = callback(obj);
       if (obj == null) break;
     }

pkg/dev_compiler/lib/js/es6/dart_sdk.js

@@ -1019,6 +1019,7 @@ dart.registerExtension = function(jsType, dartExtType) {
   if (!jsType) return;
   let extProto = dartExtType.prototype;
   let jsProto = jsType.prototype;
+  if (!jsProto) return;
   jsProto[dart._extensionType] = dartExtType;
   dart._installProperties(jsProto, extProto);
   let originalSigFn = dart.getOwnPropertyDescriptor(dartExtType, dart._methodSig).get;
@@ -1759,7 +1760,7 @@ dart.stackTrace = function(exception) {
 };
 dart.nullSafe = function(obj, ...callbacks) {
   if (obj == null) return obj;
-  for (const callback of callbacks) {
+  for (let callback of callbacks) {
     obj = callback(obj);
     if (obj == null) break;
   }

pkg/dev_compiler/lib/js/legacy/dart_sdk.js

@@ -1022,6 +1022,7 @@ dart_library.library('dart_sdk', null, /* Imports */[
     if (!jsType) return;
     let extProto = dartExtType.prototype;
     let jsProto = jsType.prototype;
+    if (!jsProto) return;
     jsProto[dart._extensionType] = dartExtType;
     dart._installProperties(jsProto, extProto);
     let originalSigFn = dart.getOwnPropertyDescriptor(dartExtType, dart._methodSig).get;
@@ -1762,7 +1763,7 @@ dart_library.library('dart_sdk', null, /* Imports */[
   };
   dart.nullSafe = function(obj, ...callbacks) {
     if (obj == null) return obj;
-    for (const callback of callbacks) {
+    for (let callback of callbacks) {
       obj = callback(obj);
       if (obj == null) break;
     }

pkg/dev_compiler/package.json

@@ -22,8 +22,10 @@
     "karma-chai": "^0.1.0",
     "karma-chrome-launcher": "^0.1.8",
     "karma-electron-launcher": "^0.0.5",
+    "karma-firefox-launcher": "~0.1",
     "karma-mocha": "^0.1.10",
     "karma-requirejs": "^0.2.2",
+    "karma-safari-launcher": "^1.0.0",
     "mocha": "^2.2.4",
     "requirejs": "^2.1.17",
     "webdriver-manager": "8.0.0"

pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/classes.dart

@@ -422,6 +422,10 @@ registerExtension(jsType, dartExtType) => JS(
   let extProto = $dartExtType.prototype;
   let jsProto = $jsType.prototype;
 
+  // TODO(vsm): This sometimes doesn't exist on FF.  These types will be
+  // broken.
+  if (!jsProto) return;
+
   // Mark the JS type's instances so we can easily check for extensions.
   jsProto[$_extensionType] = $dartExtType;
   $_installProperties(jsProto, extProto);

pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/operations.dart

@@ -509,7 +509,7 @@ stackTrace(exception) => JS('', '''(() => {
 ///
 nullSafe(obj, @rest callbacks) => JS('', '''(() => {
   if ($obj == null) return $obj;
-  for (const callback of $callbacks) {
+  for (let callback of $callbacks) {
     $obj = callback($obj);
     if ($obj == null) break;
   }