Remove base::is_*assignable as these are now in the linux sysroot.

These were needed when the sysroot's c++ library omitted these, but
now it is included with libstdc++4.8.

R=thakis@chromium.org
BUG=554293

Review-Url: https://codereview.chromium.org/2790403003
Cr-Commit-Position: refs/heads/master@{#461830}


CrOS-Libchrome-Original-Commit: 560f5dd2e3a84abf0804bfdf6463311a7d0b88bb
3 files changed
tree: 731b89c2be9401dabf90426bb3d60949d2545cc5
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/