Refactor FileSystem.
Add global FileSystem registry for new FileSystem Support later. New file system will need to implement PepperFileSystemRegistry::FileSystemPeeker for FileRef to access.
Due to the fact that 1) FileSystem and FileRef are tightly couple, 2) we wants to move both of them to browser together, there are two temporary changes in this CL.
1. webkit/plugins/ppapi/ppb_file_ref_impl.cc needs some delegation to access content::PepperFileSystemHost. The delegation code should be removed after FileRef is moved to content.
2. PepperFileSystemHost stays in renderer for now, and will be moved to browser together in the FileRef refactoring.
Also, NullFileSystemCallbackDispatcher is added with default NOTREACHED callbacks.
TEST=browser_tests --gtest_filter='*PPAPI*.*File*'
BUG=227033
Review URL: https://chromiumcodereview.appspot.com/13726024
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@193995 0039d316-1c4b-4281-b951-d872f2087c98
41 files changed
