Regarding the stencil mask value tests, fast/canvas/webgl/gl-get-calls.html seems obsolete compared to webgl/1.0.2/resources/webgl_test_files/conformance/state/gl-get-calls.html.
Created attachment 261220 [details] Patch
Copied from the webgl/1.0.2/resources/webgl_test_files/conformance/state/gl-get-calls.html. https://github.com/KhronosGroup/WebGL/commit/b540926f97e5566d4d5fbdc3539ff19910734f7e It seems that there is a difference in the way that glGetIntegerV returns an unsigned int type value among OpenGL implementatios. Some return the whole bits of value(e.g., 0xffffffff -> 0xffffffff), whereas some(e.g., ANGLE) return a max-int-clamped value(e.g., 0xffffffff -> 0x7fffffff). It would be good to make this test independent on the OpenGL implementations.
Comment on attachment 261220 [details] Patch Clearing flags on attachment: 261220 Committed r189838: <http://trac.webkit.org/changeset/189838>
All reviewed patches have been landed. Closing bug.