Compile error on clang:
src/libANGLE/Display.cpp:259:23: error: allocation of incomplete type 'egl::Device'
        mDevice = new Device(this, impl);
                      ^~~~~~
src/libANGLE/Display.h:36:7: note: forward declaration of 'egl::Device'
class Device;
      ^
In file included from src/libANGLE/Display.cpp:11:
In file included from src/libANGLE/Display.h:17:
In file included from src/libANGLE/Error.h:80:
In file included from src/libANGLE/Error.inl:9:
src/common/angleutils.h:66:5: error: deleting pointer to incomplete type 'egl::Device' may cause undefined behavior [-Werror,-Wdelete-incomplete]
    delete resource;
    ^      ~~~~~~~~
src/libANGLE/Display.cpp:209:5: note: in instantiation of function template specialization 'SafeDelete<egl::Device>' requested here
    SafeDelete(mDevice);
    ^
src/libANGLE/Display.h:36:7: note: forward declaration of 'egl::Device'
class Device;
      ^
2 errors generated.

This reverts commit 6dacaff4.

Change-Id: Ide348e156324a5af668604362c0b249ea73b6083
Reviewed-on: https://chromium-review.googlesource.com/265626Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>