Removed simple tests steps from CanvasTest.

CanvasTest only checks if the state of the different canvas
implementations are consistent with the one of the default
implementation.

Because most of the draw calls are stateless and already tested in GMs
the test steps that exercices them are not useful.

BUG=skia:3054

Review URL: https://codereview.chromium.org/672273002
1 file changed