Migrate multimedia support code to new chromium_impl structure.

Migrate multimedia support code to new chromium_impl structure.

The code implements internal chromium interfaces so it belongs in
chromium part of new project structure. The expectation is it'll be
possible to use it from both xwalk/content_shell and EWK.

Due to the fact that xwalk gyp files
(xwalk/build/xwalk_filename_rules.gypi) exclude files with tizen in
their path from build if tizen gyp variable is set to 0 the code had to
be renamed. These files were renamed to have the "efl" suffix instead, given
that there were no Tizen specific (desktop build also builds them).
This way we still keep the ability to build and test the code on desktop.

Change-Id: Ic967fb97131152494520ac9232b986126918c969
Signed-off-by: Piotr Tworek <p.tworek@samsung.com>
Signed-off-by: Taeho Kim <th81.kim@samsung.com>