Build break on Windows due to a rebase conflict (relocated header)

24>..\..\src\tests\gl_tests\SixteenBppTextureTest.cpp(9): fatal error C1083: Cannot open include file: 'end2end_tests/ANGLETest.h': No such file or directory

BUG=angleproject:1002
This reverts commit 5224926d.

Change-Id: I4ed4e918ca5bcd85367ed3e364e29039fcdf5619
Reviewed-on: https://chromium-review.googlesource.com/272542Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>