Modify source path for wpt test of Accept-CH

This CL modifies source path that is used in wpt test of Accept-CH.
window.open() uses the base URL of the entry realm's window in order to
resolve a relative URL.
The entry realm should be main window on calling function
|acceptChLoaded| as a listener for load event of non-main window in this
test.
We want to open do_not_expect_client_hints_headers.html in resources/
so the relative URL in this test should start from "resources/".

Also, entry realm is not set correctly by current chromium
implementation, so fixed test is assumed to fail.

Change-Id: I973393e0a7ca74cac882eb58f5a58aa9a81556ff
Reviewed-on: https://chromium-review.googlesource.com/1179511
Commit-Queue: Yuki Yamada <yukiy@google.com>
Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Reviewed-by: Yuki Shiino <yukishiino@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Hitoshi Yoshida <peria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584958}

third_party/WebKit/LayoutTests/TestExpectations

@@ -5019,3 +5019,7 @@ crbug.com/873829 [ Mac ] virtual/mouseevent_fractional/fast/events/autoscroll-if
 # Failures on 32-bit Android when using GPU instead of software rendering
 crbug.com/875172 [ Android ] external/wpt/web-animations/interfaces/Animatable/animate.html [ Pass Failure ]
 crbug.com/875172 [ Android ] http/tests/worklet/webexposed/global-interface-listing-paint-worklet.html [ Pass Failure ]
+
+# Does not set correct realm as scope in current implementation
+crbug.com/872138 external/wpt/client-hints/accept_ch.tentative.https.html [ Timeout Pass ]
+

third_party/WebKit/LayoutTests/external/wpt/client-hints/accept_ch.tentative.https.html

@@ -52,7 +52,7 @@ async_test(t => {
 function acceptChLoaded() {
   // Open a new window. Verify that the user agent does not attach the client
   // hints.
-  var verify_win = window.open("do_not_expect_client_hints_headers.html");
+  var verify_win = window.open("resources/do_not_expect_client_hints_headers.html");
   assert_not_equals(verify_win, null, "Popup windows not allowed?");
 }