Make canvas perf tests run less than 6 sec.

Perf tests in PerformanceTests/Canvas usually run 6 times; 1 for warm-up, 5 for data.
Currently, upload-canvas-2d-to-texture.html takes ~72 sec on Intel Ivy Bridge. If we have
Android perf bot, this perf test takes huge time.

upload-canvas-2d-to-texture.html calls glTexImage2d() 1000 times per one run. Ivy Bridge
without Accelerated 2D Canvas can call glTexImage2d() ~85 times/sec, so one run takes
12 sec, and 6 runs take 72 sec.

This CL limits 1 sec per one run for all canvas perf tests. To apply common logic to 6 tests,
this CL introduces canvas_runner.js, which is a wrapper of PerformanceTests/resources/runner.js.
canvas_runner.js makes sure that one run takes less than 1 sec. The algorithm is 
min(1 sec, time to call api 1000 times).

This CL effects test results slightly, because now upload-canvas-2d-to-texture.html takes
6 sec, instead of 72 sec.

BUG=242244
NOTRY=true

Review URL: https://codereview.chromium.org/200253002

git-svn-id: svn://svn.chromium.org/blink/trunk@170288 bbb929c8-8fbe-4397-9dbb-9b2b20218538