Reviewed by Chris Marrin.

        Multiple accelerated 2D canvases should be able to use the same GraphicsContext3D
        https://bugs.webkit.org/show_bug.cgi?id=44926

        This allows many accelerated 2d canvases to render using a single underlying GraphicsContext3D.
        It introduces a new class SharedGraphicsContext3D that manages several callers.  This class could
        also cache the current state to avoid issuing redundant calls, although in this first cut it doesn't.
        The SharedGraphicsContext3D is provided through the ChromeClient so that its lifetime can be tied to that
        of the platform-specific compositor infrastructure.

        Accelerated 2d canvases maintain a reference to a SharedGraphicsContext3D and have ownership of a CanvasFramebuffer,
        which represents the canvas's rendering target.  The compositing layer for an accelerated 2d canvas is
        aware only of the canvas's CanvasFramebuffer.  This means that WebGL and 2d canvases are no longer treated
        as the same time of layer by the compositor.

        Covered by existing canvas tests.

        * WebCore.gypi:
        * html/canvas/CanvasRenderingContext.cpp:
        * html/canvas/CanvasRenderingContext.h:
        (WebCore::CanvasRenderingContext::paintsIntoCanvasBuffer):
        (WebCore::CanvasRenderingContext::platformLayer):
        * html/canvas/CanvasRenderingContext2D.cpp:
        (WebCore::CanvasRenderingContext2D::CanvasRenderingContext2D):
        (WebCore::CanvasRenderingContext2D::paintsIntoCanvasBuffer):
        (WebCore::CanvasRenderingContext2D::reset):
        (WebCore::CanvasRenderingContext2D::didDraw):
        (WebCore::CanvasRenderingContext2D::platformLayer):
        * html/canvas/CanvasRenderingContext2D.h:
        * html/canvas/WebGLRenderingContext.cpp:
        (WebCore::WebGLRenderingContext::paintsIntoCanvasBuffer):
        * html/canvas/WebGLRenderingContext.h:
        (WebCore::WebGLRenderingContext::graphicsContext3D):
        (WebCore::WebGLRenderingContext::platformLayer):
        * loader/EmptyClients.h:
        (WebCore::EmptyChromeClient::attachRootGraphicsLayer):
        (WebCore::EmptyChromeClient::setNeedsOneShotDrawingSynchronization):
        (WebCore::EmptyChromeClient::scheduleCompositingLayerSync):
        * page/ChromeClient.h:
        (WebCore::ChromeClient::getSharedGraphicsContext3D):
        * platform/graphics/GraphicsContext.cpp:
        (WebCore::GraphicsContext::setSharedGraphicsContext3D):
        (WebCore::GraphicsContext::syncSoftwareCanvas):
        * platform/graphics/GraphicsContext.h:
        * platform/graphics/chromium/Canvas2DLayerChromium.cpp: Added.
        (WebCore::Canvas2DLayerChromium::create):
        (WebCore::Canvas2DLayerChromium::Canvas2DLayerChromium):
        (WebCore::Canvas2DLayerChromium::~Canvas2DLayerChromium):
        (WebCore::Canvas2DLayerChromium::updateContents):
        (WebCore::Canvas2DLayerChromium::setTextureChanged):
        (WebCore::Canvas2DLayerChromium::textureId):
        * platform/graphics/chromium/Canvas2DLayerChromium.h: Added.
        (WebCore::Canvas2DLayerChromium::drawsContent):
        * platform/graphics/chromium/CanvasLayerChromium.cpp:
        (WebCore::CanvasLayerChromium::CanvasLayerChromium):
        (WebCore::CanvasLayerChromium::~CanvasLayerChromium):
        (WebCore::CanvasLayerChromium::draw):
        * platform/graphics/chromium/CanvasLayerChromium.h:
        * platform/graphics/chromium/DrawingBufferChromium.cpp: Added.
        (WebCore::generateColorTexture):
        (WebCore::DrawingBuffer::DrawingBuffer):
        (WebCore::DrawingBuffer::~DrawingBuffer):
        (WebCore::DrawingBuffer::publishToPlatformLayer):
        (WebCore::DrawingBuffer::reset):
        (WebCore::DrawingBuffer::platformLayer):
        * platform/graphics/chromium/GLES2Canvas.cpp:
        (WebCore::GLES2Canvas::GLES2Canvas):
        (WebCore::GLES2Canvas::~GLES2Canvas):
        (WebCore::GLES2Canvas::bindFramebuffer):
        (WebCore::GLES2Canvas::clearRect):
        (WebCore::GLES2Canvas::fillRect):
        (WebCore::GLES2Canvas::drawTexturedRect):
        (WebCore::GLES2Canvas::drawTexturedRectTile):
        (WebCore::GLES2Canvas::drawQuad):
        (WebCore::GLES2Canvas::createTexture):
        (WebCore::GLES2Canvas::getTexture):
        * platform/graphics/chromium/GLES2Canvas.h:
        (WebCore::GLES2Canvas::context):
        (WebCore::GLES2Canvas::drawingBuffer):
        * platform/graphics/chromium/GraphicsLayerChromium.cpp:
        (WebCore::GraphicsLayerChromium::setContentsToCanvas):
        * platform/graphics/chromium/GraphicsLayerChromium.h:
        * platform/graphics/chromium/WebGLLayerChromium.cpp: Added.
        (WebCore::WebGLLayerChromium::create):
        (WebCore::WebGLLayerChromium::WebGLLayerChromium):
        (WebCore::WebGLLayerChromium::updateContents):
        (WebCore::WebGLLayerChromium::setContext):
        * platform/graphics/chromium/WebGLLayerChromium.h: Added.
        (WebCore::WebGLLayerChromium::drawsContent):
        * platform/graphics/gpu/DrawingBuffer.cpp: Added.
        (WebCore::DrawingBuffer::create):
        (WebCore::DrawingBuffer::bind):
        (WebCore::DrawingBuffer::setWillPublishCallback):
        * platform/graphics/gpu/DrawingBuffer.h: Added.
        (WebCore::DrawingBuffer::size):
        * platform/graphics/gpu/SharedGraphicsContext3D.cpp: Added.
        (WebCore::SharedGraphicsContext3D::create):
        (WebCore::SharedGraphicsContext3D::SharedGraphicsContext3D):
        (WebCore::SharedGraphicsContext3D::~SharedGraphicsContext3D):
        (WebCore::SharedGraphicsContext3D::makeContextCurrent):
        (WebCore::SharedGraphicsContext3D::scissor):
        (WebCore::SharedGraphicsContext3D::enable):
        (WebCore::SharedGraphicsContext3D::disable):
        (WebCore::SharedGraphicsContext3D::clearColor):
        (WebCore::SharedGraphicsContext3D::clear):
        (WebCore::SharedGraphicsContext3D::drawArrays):
        (WebCore::SharedGraphicsContext3D::getError):
        (WebCore::SharedGraphicsContext3D::getIntegerv):
        (WebCore::SharedGraphicsContext3D::createFramebuffer):
        (WebCore::SharedGraphicsContext3D::createTexture):
        (WebCore::SharedGraphicsContext3D::deleteFramebuffer):
        (WebCore::SharedGraphicsContext3D::deleteTexture):
        (WebCore::SharedGraphicsContext3D::framebufferTexture2D):
        (WebCore::SharedGraphicsContext3D::texParameteri):
        (WebCore::SharedGraphicsContext3D::texImage2D):
        (WebCore::SharedGraphicsContext3D::texSubImage2D):
        (WebCore::SharedGraphicsContext3D::readPixels):
        (WebCore::SharedGraphicsContext3D::supportsBGRA):
        (WebCore::SharedGraphicsContext3D::getTexture):
        (WebCore::SharedGraphicsContext3D::applyCompositeOperator):
        (WebCore::SharedGraphicsContext3D::useQuadVertices):
        (WebCore::SharedGraphicsContext3D::setActiveTexture):
        (WebCore::SharedGraphicsContext3D::bindTexture):
        (WebCore::SharedGraphicsContext3D::useFillSolidProgram):
        (WebCore::SharedGraphicsContext3D::useTextureProgram):
        (WebCore::SharedGraphicsContext3D::bindFramebuffer):
        (WebCore::SharedGraphicsContext3D::setViewport):
        (WebCore::SharedGraphicsContext3D::paintsIntoCanvasBuffer):
        * platform/graphics/gpu/SharedGraphicsContext3D.h: Added.
        * platform/graphics/gpu/Texture.cpp:
        * platform/graphics/skia/GraphicsContextSkia.cpp:
        (WebCore::GraphicsContext::syncSoftwareCanvas):
        (WebCore::GraphicsContext::setSharedGraphicsContext3D):
        * platform/graphics/skia/ImageSkia.cpp:
        * platform/graphics/skia/PlatformContextSkia.cpp:
        (WebCore::PlatformContextSkia::~PlatformContextSkia):
        (WebCore::WillPublishCallbackImpl::create):
        (WebCore::WillPublishCallbackImpl::willPublish):
        (WebCore::WillPublishCallbackImpl::WillPublishCallbackImpl):
        (WebCore::PlatformContextSkia::setSharedGraphicsContext3D):
        (WebCore::PlatformContextSkia::uploadSoftwareToHardware):
        (WebCore::PlatformContextSkia::readbackHardwareToSoftware):
        * platform/graphics/skia/PlatformContextSkia.h:
        * rendering/RenderLayerBacking.cpp:
        (WebCore::RenderLayerBacking::updateGraphicsLayerConfiguration):
2010-09-03  James Robinson  <jamesr@chromium.org>

        Reviewed by Chris Marrin.

        Multiple accelerated 2D canvases should be able to use the same GraphicsContext3D
        https://bugs.webkit.org/show_bug.cgi?id=44926

        Adds a SharedContext3D to WebViewImpl. The SharedContext3D has to live on WebViewImpl to be
        tied to the lifetime of the compositor context.

        * src/ChromeClientImpl.cpp:
        (WebKit::ChromeClientImpl::getSharedGraphicsContext3D):
        * src/ChromeClientImpl.h:
        * src/GraphicsContext3D.cpp:
        (WebCore::GraphicsContext3DInternal::initialize):
        (WebCore::GraphicsContext3DInternal::platformLayer):
        (WebCore::GraphicsContext3D::platformLayer):
        * src/WebViewImpl.cpp:
        (WebKit::WebViewImpl::getSharedGraphicsContext3D):
        * src/WebViewImpl.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@66746 268f45cc-cd09-0410-ab3c-d52691b4dbfc