https://bugs.webkit.org/show_bug.cgi?id=126216

Reviewed by Gustavo Noronha Silva.

.:

* Source/cmake/OptionsGTK.cmake: Pre-define the main derived sources directories
so that they definitions can be shared easily throughout the build system.

Source/WebCore:

* PlatformGTK.cmake: Use the new directory variables.

Source/WebKit:

* PlatformGTK.cmake: Use the new derived source variables.

Source/WebKit2:

* PlatformGTK.cmake: Use the new derived sources variables.
* UIProcess/API/gtk/tests/CMakeLists.txt: Ditto.

Tools:

* DumpRenderTree/PlatformGTK.cmake: Use the new derived sources variables.
* GtkLauncher/CMakeLists.txt: Ditto.
* MiniBrowser/gtk/CMakeLists.txt: Ditto.
* TestWebKitAPI/CMakeLists.txt: Now that the EFL and GTK+ forwarding header locations differ,
move the platform-specific includes to the EFL and GTK platform files. Also clean up forwarding
header generation into on target.
* TestWebKitAPI/PlatformEfl.cmake: Added EFL-specific locations to the include list.
* TestWebKitAPI/PlatformGTK.cmake: Added GTK-specific locations to the include list.
* WebKitTestRunner/CMakeLists.txt: Same as for TestWebKitAPI.
* WebKitTestRunner/PlatformEfl.cmake: Ditto.
* WebKitTestRunner/PlatformGTK.cmake: Ditto.
* gtk/generate-gtkdoc: Update to select the appropriate derived sources locations for
the cmake build.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@161068 268f45cc-cd09-0410-ab3c-d52691b4dbfc