Per recent WebGL specification changes, if a vertex attribute is enabled as an array but has not been bound to a buffer object by a pair of calls to bindBuffer / vertexAttribPointer, calls to drawArrays and drawElements must generate an INVALID_OPERATION error.
Created attachment 58386 [details] patch
Comment on attachment 58386 [details] patch Looks good.
Comment on attachment 58386 [details] patch ok, with a clean-up suggestion: WebCore/html/canvas/WebGLRenderingContext.cpp:2936 + m_vertexAttribState[indx].bufferBinding = m_boundArrayBuffer; Typically, we try not to abbreviate names.
Comment on attachment 58386 [details] patch Clearing flags on attachment: 58386 Committed r61006: <http://trac.webkit.org/changeset/61006>
All reviewed patches have been landed. Closing bug.