[GTK] generate-inspector-gresource-manifest.py should receive the list of files from the makefile
https://bugs.webkit.org/show_bug.cgi?id=136943

Reviewed by Philippe Normand.

Source/WebKit2:

* PlatformGTK.cmake: Fix the inspector file list and pass it to
the generate-inspector-gresource-manifest.py script.

Tools:

Update the script to receive the list of files from the command
line instead of scanning the given directories.

* gtk/generate-inspector-gresource-manifest.py:
(get_filenames): Convert filenames to use relative paths.
(find_all_files_in_directory): Deleted.
(find_all_files_in_directory.select_file): Deleted.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@173751 268f45cc-cd09-0410-ab3c-d52691b4dbfc