Delete benchmarking extension, remove API's ability to enable/disable SPDY

Delete benchmarking extension, remove API's ability to enable/disable SPDY.

Delete the "Example" benchmarking extension, as no one's using it, and
we have better tools, like WebPageReplay.  This keeps the benchmarking
API, is it's used by telemetry and WebPageReplay, but does remove the
function to enable/disable SPDY support at runtime.

This is one step towards getting rid of the SPDY configuration globals.
There are no tests for enabling/disabling SPDY when a URLRequestContext has
in-flight requests, and supporting it really doesn't get us anything.

BUG=372533
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=270811

[mmenke, 2014-05-15 15:42:48]

Chris suggested I just remove the benchmarking extension.  APIs are still
currently used by telemetry and WebPageReplay, so can't remove them (Though the
enableSpdy function is not).  May want to look at either changing that, or
moving the functions into the main benchmarking API at some point.

The extension is on the webstore, so need to figure out how to get it take down.
 Half the comments are by people who couldn't get it to work, anyways
(Presumably because it requires the command line flag --enable-net-benchmarking
to run).

[Ryan Hamilton, 2014-05-15 17:12:01]

LGTM, although there are a couple of files in the extension that appear to now
be empty instead of being removed. Is this a glitch in the codereview tool?
Should they be removed?

[mmenke, 2014-05-15 17:15:51]

On 2014/05/15 17:12:01, Ryan Hamilton wrote:
> LGTM, although there are a couple of files in the extension that appear to now
> be empty instead of being removed. Is this a glitch in the codereview tool?
> Should they be removed?

Thanks for pointing that out!  Looks like a glitch to me.  From the patch:

Index: chrome/common/extensions/docs/examples/extensions/benchmark/options.html
diff --git
a/chrome/common/extensions/docs/examples/extensions/benchmark/options.html
b/chrome/common/extensions/docs/examples/extensions/benchmark/options.html
deleted file mode 100644

I'll keep an eye on the files after landing, to make sure they're really gone.

[Ryan Hamilton, 2014-05-15 17:16:33]

SGTM

[mmenke, 2014-05-15 18:03:22]

Kalman:  Please review
chrome/common/extensions/docs/examples/extensions/benchmark/ (Note that the
entire directory is just being deleted).  I don't suppose you know how to go
about getting the benchmarking extension on the Chrome Web store taken down? 
Looks like none of the guys who worked on it are still at Google.

sky:  Please review chrome/browser and chrome/common changes.

tsepez:  Please review chrome/common/benchmarking_messages.h (Just removing a
message.  It requires a command line flag, anyways.)

[mmenke, 2014-05-15 18:04:09]

Oh, and sky:  In your portion of the code, I'm just removing a function in the
benchmarking extension, nothing exciting.

[Tom Sepez, 2014-05-15 18:34:36]

Rubberstamp LGTM on deleting message. Thanks.

[not at google - send to devlin, 2014-05-15 19:21:46]

lgtm

[sky, 2014-05-15 19:29:02]

LGTM

[mmenke, 2014-05-15 19:40:14]

On 2014/05/15 19:29:02, sky wrote:
> LGTM

Thanks everyone!

[mmenke, 2014-05-15 19:40:22]

The CQ bit was checked by mmenke@chromium.org

[commit-bot: I haz the power, 2014-05-15 19:40:54]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mmenke@chromium.org/280383008/60001

[commit-bot: I haz the power, 2014-05-15 20:47:22]

FYI, CQ is re-trying this CL (attempt #1).
Please consider checking whether the failures are real,
and report flakes to chrome-troopers@google.com.
The failing builders are:
  ios_rel_device_ninja on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/ios_rel_device_ninja/...)

[commit-bot: I haz the power, 2014-05-15 20:54:53]

Change committed as 270811