Fix expectations for fast/dom/Range/getClientRects.html

This test was converted to testharness in CL[1], but
two of cases started to fail only on Windows in CL:458377.
Since Linux searches baselines for linux -> win -> generic,
win expectations affects linux expectaions as well.

This patch fixes non-Windows expectations by adding linux
pass expectations.

[1] https://codereview.chromium.org/2475393002

Change-Id: I3ba07b9ad190b86b73f5ac0c41e9debf1d5e7eda
Reviewed-on: https://chromium-review.googlesource.com/989517Reviewed-by: Emil A Eklund <eae@chromium.org>
Reviewed-by: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#547672}

third_party/WebKit/LayoutTests/TestExpectations

@@ -1618,7 +1618,6 @@ crbug.com/626703 http/tests/devtools/extensions/extensions-sidebar.js [ Pass Fai
 crbug.com/751952 external/wpt/editing/run/forwarddelete.html [ Failure Pass Timeout ]
 crbug.com/751952 fast/text/international/complex-text-rectangle.html [ Timeout Pass ]
 crbug.com/751952 editing/selection/modify_extend/extend_by_character.html [ Pass Failure ]
-crbug.com/751952 fast/dom/Range/getClientRects.html [ Pass Failure ]
 crbug.com/751952 http/tests/devtools/console/console-uncaught-promise.js [ Pass Failure ]
 crbug.com/751952 virtual/origin-trials-runtimeflags-disabled/http/tests/origin_trials/webexposed/budget-api-origin-trial-interfaces.html [ Pass Failure ]
 

third_party/WebKit/LayoutTests/platform/linux/fast/dom/Range/getClientRects-expected.txt

+This is a testharness.js-based test.
+PASS range.selectNode(container) has rects for container and each line.
+PASS range.selectNodeContents(container) has rects for each line.
+PASS range.setStart/setEnd(node, offset) has rects for each line in range.
+PASS range.selectNode(container) should not include rect of image.
+PASS range.setStart/setEnd(node, offset) should include rect of image.
+PASS range.selectNode(container) should not include green/blue boxes.
+PASS range.selectNodeContents() should select green but not blue box.
+PASS transform, range.selectNodeContents() has rects for each line.
+PASS vertical, range.selectNodeContents() has rects for each line.
+Harness: the test ran to completion.
+