Reduce code duplication across sendBeacon() overloads.

Reduce code duplication across sendBeacon() overloads.

Rework the construction of the Beacon requests across the various supported
payload types, avoiding duplication of type-independent boilerplate code.

On linux64-release, reduces code size from 30k to 15k.

R=mkwst
BUG=

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=189790

[sof, 2015-02-09 08:31:23]

sigbjornf@opera.com changed reviewers:
+ japhet@chromium.org, mkwst@chromium.org

[sof, 2015-02-09 08:31:23]

Please take a look.

[Mike West, 2015-02-09 09:10:09]

Hrm. I'm a lot surprised that this saves 15k, but I'm happy to see the savings.
The implementation LGTM.

[sof, 2015-02-09 09:54:02]

On 2015/02/09 09:10:09, Mike West wrote:
> Hrm. I'm a lot surprised that this saves 15k, but I'm happy to see the
savings.
> The implementation LGTM.

Yes, I suspect the compiler may have traded space for (perceived) performance
and inlined the two local helper functions that was there previously.

The itch scratched here was to reduce the slight repetition in logic seen across
these sendBeacon() overloads, not so much going after .o reductions.

[sof, 2015-02-09 10:08:54]

The CQ bit was checked by sigbjornf@opera.com

[commit-bot: I haz the power, 2015-02-09 10:09:26]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/864163004/1

[commit-bot: I haz the power, 2015-02-09 10:25:45]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=189790