WebMidi: stop using testRunner.setMIDISysexPermision and remove ClientMock.

LayoutTests/webmidi/permission.html

Index: LayoutTests/webmidi/permission.html
diff --git a/LayoutTests/webmidi/permission.html b/LayoutTests/webmidi/permission.html
index 60c9e31eb2c68d341f1a1fc68c8a315cd393ee83..32946146a919b2663a4ef80921d509b66e81d345 100644
--- a/LayoutTests/webmidi/permission.html
+++ b/LayoutTests/webmidi/permission.html
@@ -9,7 +9,6 @@
 description("Test if sysex permission request is handled.");
 
 shouldBeDefined("testRunner.setPermission");
-shouldBeDefined("testRunner.setMIDISysexPermission");
 shouldBeDefined("navigator.requestMIDIAccess");
 
 window.jsTestIsAsync = true;
@@ -21,7 +20,6 @@ var finishSuccessfully = function () {
 
 var rejectSysex = function (next) {
     testRunner.setPermission('midi-sysex', 'denied', location.origin, location.origin);
-    testRunner.setMIDISysexPermission(false);
     promise = navigator.requestMIDIAccess({sysex: true});
     shouldBeDefined("promise");
     shouldBeDefined("promise.then");
@@ -39,7 +37,6 @@ var rejectSysex = function (next) {
 
 var acceptSysex = function (next) {
     testRunner.setPermission('midi-sysex', 'granted', location.origin, location.origin);
-    testRunner.setMIDISysexPermission(true);
     promise = navigator.requestMIDIAccess({sysex: true});
     shouldBeDefined("promise");
     shouldBeDefined("promise.then");