Revert 195265 "Improved extension activity logging for the chrom..."

Revert 195265 "Improved extension activity logging for the chrom..."
Hi Michael, drovering this for you while you fix the memory leak.

> Improved extension activity logging for the chrome.webRequest API.
> 
> Add a new type of log item in the activitylog_urls table: WEBREQUEST,
> used to summarize the changes made to an HTTP request using the
> blocking WebRequest extension API.  The types of modifications made
> are always logged when the extension activity log is enabled; the
> details of the modification are only kept if the activity log testing
> flag is enabled (as the details may contain sensitive data).
> 
> BUG=169628
> 
> Review URL: https://chromiumcodereview.appspot.com/12491012

TBR=mvrable@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=195311

[felt, 2013-04-19 22:19:02]

Committed patchset #1 manually as r195311.

[mvrable, 2013-04-19 22:29:00]

lgtm