[clang-tidy] Readability fixes for src/components/[m-p].*

- Get rid of redundant .c_str() for std::string,
- Get rid of redundant .get() for std::unique_ptr,
- Get rid of redundant member initializations
- Replace NULL -> nullptr.

R=blundell@chromium.org, caitkp@chromium.org, jochen@chromium.org, meacer@chromium.org, sdefresne@chromium.org

Change-Id: Ibcd0f6ad0ab6610a334fb4a5309caa6ad00b5766
Reviewed-on: https://chromium-review.googlesource.com/1046085
Commit-Queue: Alexander Yashkin <a-v-y@yandex-team.ru>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Mustafa Emre Acer <meacer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557807}

CrOS-Libchrome-Original-Commit: 3c5a779eb97321edd9a10d499c4db8d5e2e56b88
7 files changed
tree: 19c110093aab274947c631ecfc2d6ac695d67205
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/