Down Integrate Internal Changes

js/binary/decoder.js

diff --git a/js/binary/decoder.js b/js/binary/decoder.js
index e0cd12e..75d4ff7 100644
--- a/js/binary/decoder.js
+++ b/js/binary/decoder.js
@@ -180,9 +180,9 @@
 jspb.BinaryDecoder.prototype.setBlock =
     function(data, opt_start, opt_length) {
   this.bytes_ = jspb.utils.byteSourceToUint8Array(data);
-  this.start_ = goog.isDef(opt_start) ? opt_start : 0;
-  this.end_ =
-      goog.isDef(opt_length) ? this.start_ + opt_length : this.bytes_.length;
+  this.start_ = (opt_start !== undefined) ? opt_start : 0;
+  this.end_ = (opt_length !== undefined) ? this.start_ + opt_length :
+                                           this.bytes_.length;
   this.cursor_ = this.start_;
 };
 

js/binary/encoder.js

diff --git a/js/binary/encoder.js b/js/binary/encoder.js
index 0387f04..726481b 100644
--- a/js/binary/encoder.js
+++ b/js/binary/encoder.js
@@ -414,7 +414,7 @@
  * @param {boolean|number} value The value to write.
  */
 jspb.BinaryEncoder.prototype.writeBool = function(value) {
-  goog.asserts.assert(goog.isBoolean(value) || goog.isNumber(value));
+  goog.asserts.assert(typeof value === 'boolean' || typeof value === 'number');
   this.buffer_.push(value ? 1 : 0);
 };
 

js/binary/proto_test.js

diff --git a/js/binary/proto_test.js b/js/binary/proto_test.js
index ae31c8d..aee327a 100644
--- a/js/binary/proto_test.js
+++ b/js/binary/proto_test.js
@@ -176,7 +176,7 @@
  * @return {boolean}
  */
 function bytesCompare(arr, expected) {
-  if (goog.isString(arr)) {
+  if (typeof arr === 'string') {
     arr = goog.crypt.base64.decodeStringToUint8Array(arr);
   }
   if (arr.length != expected.length) {
@@ -481,8 +481,8 @@
     var msg = new proto.jspb.test.TestAllTypes();
 
     function assertGetters() {
-      assertTrue(goog.isString(msg.getRepeatedBytesList_asB64()[0]));
-      assertTrue(goog.isString(msg.getRepeatedBytesList_asB64()[1]));
+      assertTrue(typeof msg.getRepeatedBytesList_asB64()[0] === 'string');
+      assertTrue(typeof msg.getRepeatedBytesList_asB64()[1] === 'string');
       assertTrue(msg.getRepeatedBytesList_asU8()[0] instanceof Uint8Array);
       assertTrue(msg.getRepeatedBytesList_asU8()[1] instanceof Uint8Array);
 

js/binary/reader.js

diff --git a/js/binary/reader.js b/js/binary/reader.js
index 9e193ac..2af1a4a 100644
--- a/js/binary/reader.js
+++ b/js/binary/reader.js
@@ -445,9 +445,9 @@
  * @param {string} callbackName
  * @param {function(!jspb.BinaryReader):*} callback
  */
-jspb.BinaryReader.prototype.registerReadCallback =
-    function(callbackName, callback) {
-  if (goog.isNull(this.readCallbacks_)) {
+jspb.BinaryReader.prototype.registerReadCallback = function(
+    callbackName, callback) {
+  if (this.readCallbacks_ === null) {
     this.readCallbacks_ = {};
   }
   goog.asserts.assert(!this.readCallbacks_[callbackName]);
@@ -461,7 +461,7 @@
  * @return {*} The value returned by the callback.
  */
 jspb.BinaryReader.prototype.runReadCallback = function(callbackName) {
-  goog.asserts.assert(!goog.isNull(this.readCallbacks_));
+  goog.asserts.assert(this.readCallbacks_ !== null);
   var callback = this.readCallbacks_[callbackName];
   goog.asserts.assert(callback);
   return callback(this);

js/binary/utils.js

diff --git a/js/binary/utils.js b/js/binary/utils.js
index c2965c4..195247e 100644
--- a/js/binary/utils.js
+++ b/js/binary/utils.js
@@ -1001,7 +1001,7 @@
  * @return {string} Stringified scalar for text format.
  */
 jspb.utils.debugScalarToTextFormat = function(scalar) {
-  if (goog.isString(scalar)) {
+  if (typeof scalar === 'string') {
     return goog.string.quote(scalar);
   } else {
     return scalar.toString();

js/binary/utils_test.js

diff --git a/js/binary/utils_test.js b/js/binary/utils_test.js
index 51a9dee..e953ace 100644
--- a/js/binary/utils_test.js
+++ b/js/binary/utils_test.js
@@ -356,7 +356,7 @@
      */
     function test(x, opt_bits) {
       jspb.utils.splitFloat32(x);
-      if (goog.isDef(opt_bits)) {
+      if (opt_bits !== undefined) {
         if (opt_bits != jspb.utils.split64Low) throw 'fail!';
       }
       expect(truncate(x))
@@ -428,11 +428,11 @@
      */
     function test(x, opt_highBits, opt_lowBits) {
       jspb.utils.splitFloat64(x);
-      if (goog.isDef(opt_highBits)) {
+      if (opt_highBits !== undefined) {
         var split64High = jspb.utils.split64High;
         expect(opt_highBits.toString(16)).toEqual(split64High.toString(16));
       }
-      if (goog.isDef(opt_lowBits)) {
+      if (opt_lowBits !== undefined) {
         var split64Low = jspb.utils.split64Low;
         expect(opt_lowBits.toString(16)).toEqual(split64Low.toString(16));
       }

js/binary/writer.js

diff --git a/js/binary/writer.js b/js/binary/writer.js
index 8c5bff8..ab9a815 100644
--- a/js/binary/writer.js
+++ b/js/binary/writer.js
@@ -748,7 +748,7 @@
  */
 jspb.BinaryWriter.prototype.writeBool = function(field, value) {
   if (value == null) return;
-  goog.asserts.assert(goog.isBoolean(value) || goog.isNumber(value));
+  goog.asserts.assert(typeof value === 'boolean' || typeof value === 'number');
   this.writeFieldHeader_(field, jspb.BinaryConstants.WireType.VARINT);
   this.encoder_.writeBool(value);
 };

js/map.js

diff --git a/js/map.js b/js/map.js
index 589a293..ab852e4 100644
--- a/js/map.js
+++ b/js/map.js
@@ -208,13 +208,13 @@
   }
 };
 
-if (typeof(Symbol) != 'undefined') {
-  /** @override */
-  jspb.Map.ArrayIteratorIterable_.prototype[Symbol.iterator] = function() {
-    return this;
-  };
-}
 
+if (typeof(Symbol) != 'undefined') {
+/** @override */
+jspb.Map.ArrayIteratorIterable_.prototype[Symbol.iterator] = function() {
+  return this;
+};
+}
 
 /**
  * Returns the map's length (number of key/value pairs).

js/message.js

diff --git a/js/message.js b/js/message.js
index 52c541e..4bf0378 100644
--- a/js/message.js
+++ b/js/message.js
@@ -778,7 +778,7 @@
  * @return {?string} The field's coerced value.
  */
 jspb.Message.bytesAsB64 = function(value) {
-  if (value == null || goog.isString(value)) {
+  if (value == null || typeof value === 'string') {
     return value;
   }
   if (jspb.Message.SUPPORTS_UINT8ARRAY_ && value instanceof Uint8Array) {
@@ -800,7 +800,7 @@
   if (value == null || value instanceof Uint8Array) {
     return value;
   }
-  if (goog.isString(value)) {
+  if (typeof value === 'string') {
     return goog.crypt.base64.decodeStringToUint8Array(value);
   }
   goog.asserts.fail('Cannot coerce to Uint8Array: ' + goog.typeOf(value));
@@ -816,7 +816,7 @@
  */
 jspb.Message.bytesListAsB64 = function(value) {
   jspb.Message.assertConsistentTypes_(value);
-  if (!value.length || goog.isString(value[0])) {
+  if (!value.length || typeof value[0] === 'string') {
     return /** @type {!Array<string>} */ (value);
   }
   return goog.array.map(value, jspb.Message.bytesAsB64);
@@ -1654,8 +1654,8 @@
 
   if (!goog.isObject(field1) || !goog.isObject(field2)) {
     // NaN != NaN so we cover this case.
-    if ((goog.isNumber(field1) && isNaN(field1)) ||
-        (goog.isNumber(field2) && isNaN(field2))) {
+    if ((typeof field1 === 'number' && isNaN(field1)) ||
+        (typeof field2 === 'number' && isNaN(field2))) {
       // One of the fields might be a string 'NaN'.
       return String(field1) == String(field2);
     }

js/message_test.js

diff --git a/js/message_test.js b/js/message_test.js
index b2d0da1..e038f65 100644
--- a/js/message_test.js
+++ b/js/message_test.js
@@ -855,7 +855,7 @@
     var assertNan = function(x) {
       assertTrue(
           'Expected ' + x + ' (' + goog.typeOf(x) + ') to be NaN.',
-          goog.isNumber(x) && isNaN(x));
+          typeof x === 'number' && isNaN(x));
     };
 
     var message = new proto.jspb.test.FloatingPointFields([

js/proto3_test.js

diff --git a/js/proto3_test.js b/js/proto3_test.js
index 7f9d71d..79acc3c 100644
--- a/js/proto3_test.js
+++ b/js/proto3_test.js
@@ -54,7 +54,7 @@
  * @return {boolean}
  */
 function bytesCompare(arr, expected) {
-  if (goog.isString(arr)) {
+  if (typeof arr === 'string') {
     arr = goog.crypt.base64.decodeStringToUint8Array(arr);
   }
   if (arr.length != expected.length) {