RTCError: Make "message" optional and be the last argument.

Based on https://github.com/w3c/webrtc-pc/pull/2112.

Bug: 937844
Change-Id: I7ad149f47fb394f15055cc8fd77e79b4e5e0f317
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1499613
Commit-Queue: Henrik Boström <hbos@chromium.org>
Reviewed-by: Marina Ciocea <marinaciocea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638192}

third_party/blink/renderer/modules/peerconnection/rtc_error.cc

@@ -9,11 +9,11 @@
 namespace blink {
 
 // static
-RTCError* RTCError::Create(String message, const RTCErrorInit* init) {
-  return MakeGarbageCollected<RTCError>(std::move(message), init);
+RTCError* RTCError::Create(const RTCErrorInit* init, String message) {
+  return MakeGarbageCollected<RTCError>(init, std::move(message));
 }
 
-RTCError::RTCError(String message, const RTCErrorInit* init)
+RTCError::RTCError(const RTCErrorInit* init, String message)
     : DOMException(0u, "RTCError", std::move(message), String()),
       error_detail_(init->errorDetail()),
       sdp_line_number_(init->hasSdpLineNumber()

third_party/blink/renderer/modules/peerconnection/rtc_error.h

@@ -17,8 +17,8 @@ class RTCError final : public DOMException {
   DEFINE_WRAPPERTYPEINFO();
 
  public:
-  static RTCError* Create(String message, const RTCErrorInit* init);
-  RTCError(String message, const RTCErrorInit* init);
+  static RTCError* Create(const RTCErrorInit* init, String message);
+  RTCError(const RTCErrorInit* init, String message);
 
   const String& errorDetail() const;
   int32_t sdpLineNumber(bool& is_null) const;

third_party/blink/renderer/modules/peerconnection/rtc_error.idl

@@ -23,7 +23,7 @@ enum RTCErrorDetailType {
 
 // https://w3c.github.io/webrtc-pc/#dfn-rtcerror
 [
-    Constructor(DOMString message, RTCErrorInit init)
+    Constructor(RTCErrorInit init, optional DOMString message = "")
 ] interface RTCError : DOMException {
     readonly attribute RTCErrorDetailType errorDetail;
     readonly attribute long? sdpLineNumber;

third_party/blink/web_tests/external/wpt/webrtc/RTCError.html

@@ -8,38 +8,43 @@
 'use strict';
 
 test(() => {
-  const error = new RTCError('message', {errorDetail:'data-channel-failure'});
+  const error = new RTCError({errorDetail:'data-channel-failure'}, 'message');
   assert_equals(error.message, 'message');
   assert_equals(error.errorDetail, 'data-channel-failure');
-}, 'RTCError constructor with message and errorDetail');
+}, 'RTCError constructor with errorDetail and message');
+
+test(() => {
+  const error = new RTCError({errorDetail:'data-channel-failure'});
+  assert_equals(error.message, '');
+}, 'RTCError constructor\'s message argument is optional');
 
 test(() => {
   assert_throws(new TypeError(), () => {
-    new RTCError('message');
+    new RTCError();
   });
   assert_throws(new TypeError(), () => {
-    new RTCError();
+    new RTCError({});  // {errorDetail} is missing.
   });
-}, 'RTCError constructor throws TypeError if any argument is missing');
+}, 'RTCError constructor throws TypeError if arguments are missing');
 
 test(() => {
   assert_throws(new TypeError(), () => {
-    new RTCError('message', {errorDetail:'invalid-error-detail'});
+    new RTCError({errorDetail:'invalid-error-detail'}, 'message');
   });
 }, 'RTCError constructor throws TypeError if the errorDetail is invalid');
 
 test(() => {
-  const error = new RTCError('message', {errorDetail:'data-channel-failure'});
+  const error = new RTCError({errorDetail:'data-channel-failure'}, 'message');
   assert_equals(error.name, 'RTCError');
 }, 'RTCError.name is \'RTCError\'');
 
 test(() => {
-  const error = new RTCError('message', {errorDetail:'data-channel-failure'});
+  const error = new RTCError({errorDetail:'data-channel-failure'}, 'message');
   assert_equals(error.code, 0);
 }, 'RTCError.code is 0');
 
 test(() => {
-  const error = new RTCError('message', {errorDetail:'data-channel-failure'});
+  const error = new RTCError({errorDetail:'data-channel-failure'}, 'message');
   assert_throws(new TypeError(), () => {
     error.errorDetail = 'dtls-failure';
   });
@@ -49,9 +54,9 @@ test(() => {
   // Infers what are valid RTCErrorInit objects by passing them to the RTCError
   // constructor.
   assert_throws(new TypeError(), () => {
-    new RTCError('message', {});
+    new RTCError({}, 'message');
   });
-  new RTCError('message', {errorDetail:'data-channel-failure'});
+  new RTCError({errorDetail:'data-channel-failure'}, 'message');
 }, 'RTCErrorInit.errorDetail is the only required attribute');
 
 // All of these are number types (long or unsigned long).
@@ -63,18 +68,18 @@ const nullableAttributes = ['sdpLineNumber',
 
 nullableAttributes.forEach(attribute => {
   test(() => {
-    const error = new RTCError('message', {errorDetail:'data-channel-failure'});
+    const error = new RTCError({errorDetail:'data-channel-failure'}, 'message');
     assert_equals(error[attribute], null);
   }, 'RTCError.' + attribute + ' is null by default');
 
   test(() => {
-    const error = new RTCError('message', {errorDetail:'data-channel-failure',
-                                           [attribute]: 0});
+    const error = new RTCError(
+        {errorDetail:'data-channel-failure', [attribute]: 0}, 'message');
     assert_equals(error[attribute], 0);
   }, 'RTCError.' + attribute + ' is settable by constructor');
 
   test(() => {
-    const error = new RTCError('message', {errorDetail:'data-channel-failure'});
+    const error = new RTCError({errorDetail:'data-channel-failure'}, 'message');
     assert_throws(new TypeError(), () => {
       error[attribute] = 42;
     });