Revert of Support XI2 in PlatformKeycodeFromNative()

Revert of Support XI2 in PlatformKeycodeFromNative() (https://codereview.chromium.org/397803007/)

Reason for revert:
This is crashing on Linux ChromiumOS Tests under debug: for example http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Tests%20%28dbg%29%281%29/builds/31200/steps/unit_tests/logs/TestRewriteCapsLockToControl

Started crashing here: http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Tests%20%28dbg%29%281%29/builds/31200

Stack follows:
EventRewriterTest.TestRewriteCapsLockToControl (run #1):
[ RUN      ] EventRewriterTest.TestRewriteCapsLockToControl
Xlib:  extension "RANDR" missing on display ":9".
[442:442:0717/184628:2623724699:FATAL:events_x.cc(606)] Check failed: false.
#0 0x7fba0e7b959e base::debug::StackTrace::StackTrace()
#1 0x7fba0e84c632 logging::LogMessage::~LogMessage()
#2 0x7fba0bac8feb ui::PlatformKeycodeFromNative()
#3 0x7fba0ba8b357 ui::KeyEvent::KeyEvent()
#4 0x000000cba75a (anonymous namespace)::CheckX11KeyTestCase()
#5 0x000000caa668 (anonymous namespace)::CheckKeyTestCase()
#6 0x000000caec04 chromeos::EventRewriterTest_TestRewriteCapsLockToControl_Test::TestBody()
#7 0x000003e0f1a3 testing::internal::HandleSehExceptionsInMethodIfSupported\u003C>()
#8 0x000003dfc5ae testing::internal::HandleExceptionsInMethodIfSupported\u003C>()
#9 0x000003df3415 testing::Test::Run()
#10 0x000003df3b2b testing::TestInfo::Run()
#11 0x000003df411a testing::TestCase::Run()
#12 0x000003df8728 testing::internal::UnitTestImpl::RunAllTests()
#13 0x000003e07f33 testing::internal::HandleSehExceptionsInMethodIfSupported\u003C>()
#14 0x000003dfe0ce testing::internal::HandleExceptionsInMethodIfSupported\u003C>()
#15 0x000003df83b4 testing::UnitTest::Run()
#16 0x00000685b841 RUN_ALL_TESTS()
#17 0x00000685a8c7 base::TestSuite::Run()
#18 0x00000686d11d content::UnitTestTestSuite::Run()
#19 0x000003f15682 base::internal::RunnableAdapter\u003C>::Run()
#20 0x000003f155ec base::internal::InvokeHelper\u003C>::MakeItSo()
#21 0x000003f1559a base::internal::Invoker\u003C>::Run()
#22 0x000002e896fe base::Callback\u003C>::Run()
#23 0x0000068548d0 base::(anonymous namespace)::LaunchUnitTestsInternal()
#24 0x0000068545c7 base::LaunchUnitTests()
#25 0x000003f15365 main
#26 0x7fba06fb076d __libc_start_main
#27 0x00000076e5c9 \u003Cunknown>

Original issue's description:
> Support XI2 in PlatformKeycodeFromNative()
> 
> R=sadrul@chromium.org
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=283931

TBR=sadrul@chromium.org,kpschoedel@chromium.org
NOTREECHECKS=true
NOTRY=true

[Mike West, 2014-07-18 07:15:29]

Created Revert of Support XI2 in PlatformKeycodeFromNative()

[commit-bot: I haz the power, 2014-07-18 07:16:14]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mkwst@chromium.org/400893003/1

[Mike West, 2014-07-18 07:19:11]

The CQ bit was unchecked by mkwst@chromium.org

[Mike West, 2014-07-18 07:21:03]

This was fixed in https://codereview.chromium.org/403713002/

Thanks sadrul!