Update how SitePerProcessMacBrowserTest waits for hit test data

Currently SitePerProcessMacBrowserTest.InputEventRouterTouchpadGestureTargetTest
 does not work on Viz. This change updates it to use the new hit test data api.

TEST: SitePerProcessMacBrowserTest.InputEventRouterTouchpadGestureTargetTest
Bug: 787945
Change-Id: I5aec8787ca1cf73e04aa8801b8d6af53d471c601
Reviewed-on: https://chromium-review.googlesource.com/1099044Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Commit-Queue: Jonathan Ross <jonross@chromium.org>
Cr-Commit-Position: refs/heads/master@{#566865}

content/browser/site_per_process_mac_browsertest.mm

@@ -12,6 +12,7 @@
 #include "content/public/browser/browser_thread.h"
 #include "content/public/test/browser_test_utils.h"
 #include "content/public/test/content_browser_test_utils.h"
+#include "content/public/test/hit_test_region_observer.h"
 #include "content/public/test/test_utils.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #import "third_party/ocmock/OCMock/OCMock.h"
@@ -318,7 +319,7 @@ IN_PROC_BROWSER_TEST_F(SitePerProcessMacBrowserTest,
   // surface information required for event hit testing is ready.
   auto* rwhv_child =
       static_cast<RenderWidgetHostViewBase*>(child_frame_host->GetView());
-  WaitForChildFrameSurfaceReady(child_frame_host);
+  WaitForHitTestDataOrChildSurfaceReady(child_frame_host);
 
   // All touches & gestures are sent to the main frame's view, and should be
   // routed appropriately from there.

testing/buildbot/filters/viz.content_browsertests.filter

@@ -35,7 +35,6 @@
 -SitePerProcessHitTestBrowserTest.SurfaceHitTestPointerEventsNone*
 -SitePerProcessHitTestBrowserTest.SurfaceHitTestTest*
 -SitePerProcessHitTestBrowserTest.TouchpadPinchOverOOPIF*
--SitePerProcessMacBrowserTest.InputEventRouterTouchpadGestureTargetTest
 -SitePerProcessNonIntegerScaleFactorHitTestBrowserTest.NestedSurfaceHitTestTest*
 -SitePerProcessMouseWheelHitTestBrowserTestWheelScrollLatchingDisabled*