Import the testing/perf module from Chromium.

We can use these perf routines to make our performance test output
compatible with the Chromium perf bots.

BUG=angle:744

Change-Id: I75a44786d4521fc0c7d8226f10575fcfda0fa221
Use Chromium perf bot output style for perf test.

The Chromium style output will allow the perf bots to collect data
from our performance tests.

BUG=angle:744

Change-Id: I2ffdace688004edf2918ead2a3e2aa2a6c4daf95
Remove perf tests dependency on gtest.

BUG=angle:744

Change-Id: I9272e0009238680db1a87e6cb1c1c48b2ed48dd6
Add workaround for Unicode compile error.

Chromium builds define UNICODE, while we don't, which confuses
the built-in IDC_ARROW macro.

With this fix, and http://crbug.com/415983, we can build
angle_perf_tests in Chromium.

BUG=angle:744

Change-Id: I268a7c11a5b5355cb2485bf10faf750972cf4e30
Add rapidjson third party library.

RapidJSON gives us the ability to use JSON in our performance
tests to specific the input. The license is very permissive
and according to the author the performance is excellent.

Chromium's JSON library unfortunately seems quite tied to the
"base" project.

BUG=angle:744

Change-Id: I64e72aad1ed6fa954acd851607032cb48a461348
Use JSON as startup parameters to BufferSubData test.

BUG=angle:744

Change-Id: I60287f3c612011f505f1bc20632efc4dd17001d3
Refresh of use-json

Change-Id: I0e5fb2b7632f29bf054694333ded2b8540429018