Move tests for sendBeacon to a separate dedicated directory for clearer ownership

third_party/WebKit/LayoutTests/TestExpectations

 # Intentional failures to test the layout test system.
 Bug(intentional) [ Android Linux Win Mac10.10 Mac10.11 Retina ] harness-tests/crash.html [ Crash ]
 crbug.com/644303 [ Mac10.9 ] harness-tests/crash.html [ Crash Timeout ]
 Bug(intentional) harness-tests/timeout.html [ Timeout ]
 
 # ====== Oilpan-only failures from here ======
 # Most of these actually cause the tests to report success, rather than
 # failure. Expected outputs will be adjusted for the better once Oilpan
 # has been well and truly enabled always.
 
@@ skipping 1817 matching lines @@
 
 crbug.com/399507 [ Mac Linux Win10 ] virtual/threaded/inspector/tracing/timeline-paint/layer-tree.html [ Skip ]
 
 crbug.com/635909 inspector/sources/debugger-frameworks/frameworks-dom-xhr-event-breakpoints.html [ NeedsManualRebaseline Timeout ]
 
 crbug.com/636424 [ Win7 Debug ] editing/selection/modify_move/move-by-word-visually-crash-test-5.html [ Pass Timeout ]
 crbug.com/638618 inspector/editor/text-editor-search-switch-editor.html [ Skip ]
 
 # This test breaks when the feature introduced in the bug is enabled. We keep
 # this tested without the feature by using the virtual test. See
-# virtual/stable/http/tests/navigation/beacon-cross-origin-redirect-blob-expected.txt
-crbug.com/490015 http/tests/navigation/beacon-cross-origin-redirect-blob.html [ Skip ]
-crbug.com/490015 virtual/mojo-loading/http/tests/navigation/beacon-cross-origin-redirect-blob.html [ Skip ]
+# virtual/stable/http/tests/sendbeacon/beacon-cross-origin-redirect-blob-expected.txt
+crbug.com/490015 http/tests/sendbeacon/beacon-cross-origin-redirect-blob.html [ Skip ]
+crbug.com/490015 virtual/mojo-loading/http/tests/sendbeacon/beacon-cross-origin-redirect-blob.html [ Skip ]
 # This test doesn't need to be run with the stable release mode.
-crbug.com/490015 virtual/stable/http/tests/navigation/beacon-blob-with-non-simple-type.html [ Skip ]
+crbug.com/490015 virtual/stable/http/tests/sendbeacon/beacon-blob-with-non-simple-type.html [ Skip ]
 # This test fails with the stable release mode.
-crbug.com/490015 virtual/stable/http/tests/navigation/same-and-different-back.html [ Skip ]
+crbug.com/694958 virtual/stable/http/tests/navigation/same-and-different-back.html [ Skip ]
 
 # These tests have console error messages whose order is not deterministic.
 crbug.com/685778 http/tests/dom/promise-rejection-events.html [ Pass Failure ]
 crbug.com/685778 virtual/mojo-loading/http/tests/dom/promise-rejection-events.html [ Pass Failure ]
 
 # This test has a failure console message with specific performance
 # numbers so a consistent baseline cannot be added. This test could be
 # imported if the test passed or if the results for testharness tests
 # were matched on pass/fail but not exact error messages.
 crbug.com/688854 external/wpt/hr-time/window-worker-time-origin.html [ Failure ]
@@ skipping 733 matching lines @@
 crbug.com/688486 external/wpt/service-workers/service-worker/fetch-request-redirect.https.html [ Failure Pass ]
 crbug.com/688486 external/wpt/service-workers/service-worker/fetch-request-resources.https.html [ Failure Pass ]
 
 # Sheriff failures 2017-02-13
 crbug.com/691423 [ Mac ] fast/frames/location-change-no-file-access.html [ Failure Pass ]
 
 # Sheriff failures 2017-02-21
 crbug.com/73609 http/tests/media/video-play-stall.html [ Pass Timeout ]
 crbug.com/73609 virtual/mojo-loading/http/tests/media/video-play-stall.html [ Pass Timeout ]
 crbug.com/694467 fast/text/line-break-8bit-after-16bit.html [ Pass Failure ]