[Media Router] Update presentation URL for integration tests.

This CL changes the presentation URL for Media Router integration tests to
https:, so we can implement proper scheme handling in Blink in a future patch.

This is patch #3 in a five-patch change:

Patch #1 (google3): Deprecate test: in mr.TestProvider
Patch #2 (Chromium): Roll DEPS in Chromium
Patch #3 (Chromium): This patch
Patch #4 (google3): Remove test: from mr.TestProvider
Patch #5 (Chromium): Roll DEPS again

Bug: 825927
Change-Id: I8574be618a8005c52567750c62b1945ee9d413f7
Reviewed-on: https://chromium-review.googlesource.com/1106555Reviewed-by: Derek Cheng <imcheng@chromium.org>
Commit-Queue: mark a. foltz <mfoltz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#568580}

chrome/test/media_router/resources/common.js

@@ -21,7 +21,7 @@ if (params.get('__is_android__') == 'true') {
 } else if (params.get('__oneUANoReceiver__') == 'true') {
   presentationUrl = "no_presentation_receiver.html";
 } else {
-  presentationUrl = "test://test";
+  presentationUrl = "https://www.example.com/presentation.html";
 }
 
 var startSessionRequest = new PresentationRequest([presentationUrl]);