Make some foo.h headers usable without foo-inl.h header.

Make some foo.h headers usable without foo-inl.h header.

This CL us a pure refactoring that makes an empty compilation unit
including just "foo.h" but not "foo-inl.h" compile without warnings or
errors. This is needed to further reduce the header dependency tangle.

R=rossberg@chromium.org

Committed: https://crrev.com/8e634eaa0b9e4441b98e4c53f06f4a17af9470a8
Cr-Commit-Position: refs/heads/master@{#30158}

[rossberg, 2015-08-13 13:32:47]

lgtm

[Michael Starzinger, 2015-08-13 13:47:13]

The CQ bit was checked by mstarzinger@chromium.org

[Michael Starzinger, 2015-08-13 13:47:13]

The patchset sent to the CQ was uploaded after l-g-t-m from
rossberg@chromium.org
Link to the patchset: https://codereview.chromium.org/1290743005/#ps20001
(title: "As per offline comment.")

[commit-bot: I haz the power, 2015-08-13 13:47:21]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1290743005/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1290743005/20001

[commit-bot: I haz the power, 2015-08-13 14:02:27]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-08-13 14:02:43]

Patchset 2 (id:??) landed as
https://crrev.com/8e634eaa0b9e4441b98e4c53f06f4a17af9470a8
Cr-Commit-Position: refs/heads/master@{#30158}