Code quality and standards in SimpleBackend.

In the review of https://codereview.chromium.org/13880016/ , rvargas
pointed out that we could use WeakPtr safely in the SimpleEntryImpl,
even though it's destructed on any thread, since the WeakPtr can be
destructed on any thread.

As well, he asked for raw pointer function arguments, and some grammar
fixes.

While I was here, I delinted.

R=pliard,rvargas
BUG=233103

Review URL: https://codereview.chromium.org/14022012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@194873 0039d316-1c4b-4281-b951-d872f2087c98
9 files changed