[traceviewer] Test failures when --enable-skia-benchmarking set

[hsheth2]

When Chrome or Chromium is started with the --enable-skia-benchmarking flag set, two of the tests fail.

tracing.ui.extras.chrome.cc.picture_ops_list_view_test.instantiate  failed (1.04ms) 
TypeError: Cannot read property 'objects' of undefined
    at TestCase.testFn_ (http://127.0.0.1:8003/tracing/ui/extras/chrome/cc/picture_ops_list_view_test.html:28:24)
    at TestCase.run (http://127.0.0.1:8003/tracing/base/unittest/test_case.html:84:19)
    at TestRunner.<anonymous> (http://127.0.0.1:8003/tracing/base/unittest/test_runner.html:235:48)
    at new Promise (<anonymous>)
    at TestRunner.runCurrentTestCase_ (http://127.0.0.1:8003/tracing/base/unittest/test_runner.html:232:14)
    at TestRunner.runOneTestCase_ (http://127.0.0.1:8003/tracing/base/unittest/test_runner.html:180:12)
    at http://127.0.0.1:8003/tracing/base/unittest/test_runner.html:137:43

tracing.ui.extras.chrome.cc.picture_ops_list_view_test.selection  failed (0.67ms) 
TypeError: Cannot read property 'objects' of undefined
    at TestCase.testFn_ (http://127.0.0.1:8003/tracing/ui/extras/chrome/cc/picture_ops_list_view_test.html:42:24)
    at TestCase.run (http://127.0.0.1:8003/tracing/base/unittest/test_case.html:84:19)
    at TestRunner.<anonymous> (http://127.0.0.1:8003/tracing/base/unittest/test_runner.html:235:48)
    at new Promise (<anonymous>)
    at TestRunner.runCurrentTestCase_ (http://127.0.0.1:8003/tracing/base/unittest/test_runner.html:232:14)
    at TestRunner.runOneTestCase_ (http://127.0.0.1:8003/tracing/base/unittest/test_runner.html:180:12)
    at http://127.0.0.1:8003/tracing/base/unittest/test_runner.html:137:43

My suspicion is that the tests effectively are not run unless --enable-skia-benchmarking is set, due to an early check and return:

catapult/tracing/tracing/ui/extras/chrome/cc/picture_ops_list_view_test.html

Line 23 in 53913ce

if (!tr.e.cc.PictureSnapshot.CanRasterize()) return;

There is also be an issue in the picture_test. It appears that the undefined check is not enough to distinguish between the getOps being unavailable and incorrectly returning a falsy value. If we replaced that if statement with if (!tr.e.cc.PictureSnapshot.CanGetOps()) return;, then that test also fails when --enable-skia-benchmarking is set.

catapult/tracing/tracing/extras/chrome/cc/picture_test.html

Line 40 in 53913ce

if (!ops) return;

Tested in Chrome Version 75.0.3770.142 (Official Build) (64-bit) and Chromium Version 75.0.3770.0 (Developer Build) custom (64-bit).