Remove SkQuadTree.

Remove SkQuadTree.

We're not testing it to the same degree we do RTree and TileGrid.  Any changes
we'll make to BBH APIs become 33% easier without it.  If find we want it again,
we can always resurrect it.

BUG=skia:1021, skia:2834
TBR=reed

Committed: https://skia.googlesource.com/skia/+/2a65a238b0e688356aee09d08f3f8a317359b4d2

[mtklein, 2014-08-26 20:52:44]

mtklein@google.com changed reviewers:
+ mtklein@google.com, robertphillips@google.com

[mtklein, 2014-08-26 20:55:03]

The CQ bit was checked by mtklein@google.com

[commit-bot: I haz the power, 2014-08-26 20:56:02]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/mtklein@chromium.org/500373005/1

[commit-bot: I haz the power, 2014-08-26 20:56:03]

Note for Reviewers:
The CQ is waiting for an approval.
If you believe that the CL is not ready yet, or if you would like to L-G-T-M
with comments then please uncheck the CQ checkbox.

Waiting for LGTM from a valid reviewer till 2014-08-27 02:56 UTC

[commit-bot: I haz the power, 2014-08-26 20:56:14]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-08-26 20:56:15]

Presubmit check for 500373005-1 failed and returned exit status 1.

Running presubmit commit checks ...

** Presubmit ERRORS **
Since the CL is editing public API, you must have an LGTM from one of:
('reed@chromium.org', 'reed@google.com', 'bsalomon@chromium.org',
'bsalomon@google.com', 'djsollen@chromium.org', 'djsollen@google.com')

Presubmit checks took 2.4s to calculate.

[mtklein, 2014-08-26 20:56:55]

The CQ bit was checked by mtklein@google.com

[commit-bot: I haz the power, 2014-08-26 20:58:01]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/mtklein@chromium.org/500373005/1

[commit-bot: I haz the power, 2014-08-26 21:07:09]

Committed patchset #1 (1) as 2a65a238b0e688356aee09d08f3f8a317359b4d2

[mtklein, 2014-08-26 21:11:26]

On 2014/08/26 21:07:09, I haz the power (commit-bot) wrote:
> Committed patchset #1 (1) as 2a65a238b0e688356aee09d08f3f8a317359b4d2

OOOPS.  I did not realize that TBR=reed would go all the way through.  Was just
doing that to get the bots running...

[robertphillips, 2014-08-26 21:33:02]

lgtm