Move several annotations to annotations package.

Move AccessedByNative, CalledByNativeUnchecked and UsedByReflection to
annotations package where they belond. CalledByNative and NativeCall will
be moved in a separate CL since they touch every file under the sun.

BUG=None

Review URL: https://codereview.chromium.org/1078343002

Cr-Commit-Position: refs/heads/master@{#324983}
11 files changed