Revert of Reduce hit test on ShowPress by moving event targeting to WebViewImpl (patchset #8 of https://codereview.chromium.org/490783003/)

Reason for revert:
This is breaking content shell instrumentation tests (Chromium Android):
http://build.chromium.org/p/chromium.webkit/builders/Android%20Tests%20%28dbg%29/builds/21185/steps/contentshell_instrumentation_tests/logs/stdio

You can reproduce that by building a Chromium Android build and run:
build/android/test_runner.py instrumentation --test-apk ContentShellTest --verbose --test_data content:content/test/data/android/device_files -f AddressDetectionTest#testAddressLimits
(assuming you have content_shell_apk and content_shell_test_apk build)

Original issue's description:
> Reduce hit test on ShowPress by moving hit testing to WebViewImpl.
> 
> Previously there was a hit test for link highlighting in WebViewImpl and then a                                          
> separate one in EventHandler::handleGestureEvent. This CL makes it so that a                                             
> single hit test in WebViewImpl is reused by the EventHandler. Scroll events                                              
> still need to hit test in a separate fashion though and their handling has been                                          
> refactored into a separate code path.
> 
> BUG=381728
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=181009

TBR=aelias@chromium.org,dgozman@chromium.org,rbyers@chromium.org,zeeshanq@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=381728

Review URL: https://codereview.chromium.org/509173004

git-svn-id: svn://svn.chromium.org/blink/trunk@181030 bbb929c8-8fbe-4397-9dbb-9b2b20218538