Source/WebCore: [WebGL] Implement ANGLE_instanced_arrays

https://bugs.webkit.org/show_bug.cgi?id=127257

Reviewed by Brent Fulgham.

Implement the instanced drawing WebGL extension,
ANGLE_instanced_arrays. This is currently Mac-only,
but should be portable to other platforms if their
OpenGL exposes the functions. It's also done in a way
that will make exposing it to WebGL2 simple.

Test: fast/canvas/webgl/angle-instanced-arrays.html

* CMakeLists.txt:
* DerivedSources.cpp:
* DerivedSources.make:
* GNUmakefile.list.am:
* WebCore.vcxproj/WebCore.vcxproj:
* WebCore.vcxproj/WebCore.vcxproj.filters:
* WebCore.xcodeproj/project.pbxproj:
Add the new files to all the build systems.

* bindings/js/JSWebGLRenderingContextCustom.cpp:
(WebCore::toJS): Link JS side to C++ side.

* html/canvas/ANGLEInstancedArrays.cpp: Added.
(WebCore::ANGLEInstancedArrays::ANGLEInstancedArrays):
* html/canvas/ANGLEInstancedArrays.h: Added.
* html/canvas/ANGLEInstancedArrays.idl: Added.
New boilerplate files that expose the extension methods.

* html/canvas/WebGLExtension.h: New extension enum.

* html/canvas/WebGLRenderingContext.cpp:
(WebCore::WebGLRenderingContext::validateVertexAttributes): Add an optional
parameter representing the number of instance primitives we are asked
to draw. Use that for the draw count if looking at an instanced attribute.
Also make sure we see at least one non-instanced attribute.
(WebCore::WebGLRenderingContext::validateDrawArrays): Update this so it could
be used from either drawArrays or drawArraysInstanced.
(WebCore::WebGLRenderingContext::drawArrays):
(WebCore::WebGLRenderingContext::validateDrawElements): Same here, now can be
used by the instanced and non-instanced versions.
(WebCore::WebGLRenderingContext::drawElements):
(WebCore::WebGLRenderingContext::getExtension): Create and return the new extension.
(WebCore::WebGLRenderingContext::getSupportedExtensions): Add new extension to the list.
(WebCore::WebGLRenderingContext::getVertexAttrib): Intercept a query to the divisor
attribute and return the value we kept in the state.
(WebCore::WebGLRenderingContext::drawArraysInstanced): Call the GC3D method.
(WebCore::WebGLRenderingContext::drawElementsInstanced): Ditto.
(WebCore::WebGLRenderingContext::vertexAttribDivisor): Ditto.

* html/canvas/WebGLRenderingContext.h: Define the new methods and parameters.

* html/canvas/WebGLVertexArrayObjectOES.cpp:
(WebCore::WebGLVertexArrayObjectOES::setVertexAttribDivisor): Keep a record of the
divisor if we set it.
* html/canvas/WebGLVertexArrayObjectOES.h:
(WebCore::WebGLVertexArrayObjectOES::VertexAttribState::VertexAttribState):

* platform/graphics/GraphicsContext3D.h: New enum.
* platform/graphics/mac/GraphicsContext3DMac.mm:
(WebCore::GraphicsContext3D::drawArraysInstanced): The actual calls into OpenGL.
(WebCore::GraphicsContext3D::drawElementsInstanced): Ditto.
(WebCore::GraphicsContext3D::vertexAttribDivisor): Ditto.

* platform/graphics/opengl/GraphicsContext3DOpenGL.cpp: Empty implementations
for non-mac platforms.

* platform/graphics/ios/GraphicsContext3DIOS.h: Define the iOS names for the
functions.

LayoutTests: Implement ANGLE_instanced_arrays
https://bugs.webkit.org/show_bug.cgi?id=127257

Reviewed by Brent Fulgham.

Copied a slightly modified version of the Khronos instanced
arrays test (mostly modified due to the fact this comes from
an in-progress update to the test suite).

* fast/canvas/webgl/angle-instanced-arrays-expected.txt: Added.
* fast/canvas/webgl/angle-instanced-arrays.html: Added.
* fast/canvas/webgl/resources/webgl-test-utils.js:
(WebGLTestUtils): Added some new functions that were missing, and
some output to a checkColor test.
* platform/efl/TestExpectations: Skip this for EFL.
* platform/mac-mountainlion/fast/canvas/webgl/angle-instanced-arrays-expected.txt: Not
supported on Mountain Lion.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@162565 268f45cc-cd09-0410-ab3c-d52691b4dbfc