Use Chromium's logging utility for content files

This patch modifies all the files under content/public/android/java
to use org.chromium.base.Log instead of android.util.Log.
It also changes the log messges as per the guidelines.

BUG=472152

Review URL: https://codereview.chromium.org/1178253005

Cr-Commit-Position: refs/heads/master@{#335910}
24 files changed