Merge 92908 - Readback composited webgl results for printing

Merge 92908 - Readback composited webgl results for printing
https://bugs.webkit.org/show_bug.cgi?id=65658
BUG=55927
Patch by John Bauman <jbauman@chromium.org>; on 2011-08-11
Reviewed by James Robinson.

Source/WebCore:

The real composited results may be locked inside the compositor
context's version of a texture because the drawing buffer was
automatically cleared, so read from there to get the actual presented
version to draw.

* html/canvas/WebGLRenderingContext.cpp:
(WebCore::WebGLRenderingContext::paintRenderingResultsToCanvas):
* platform/graphics/GraphicsContext3D.h:
* platform/graphics/chromium/Extensions3DChromium.h:
* platform/graphics/chromium/WebGLLayerChromium.cpp:
(WebCore::WebGLLayerChromium::paintRenderedResultsToCanvas):
* platform/graphics/chromium/WebGLLayerChromium.h:
* platform/graphics/opengl/GraphicsContext3DOpenGL.cpp:
(WebCore::GraphicsContext3D::paintCompositedResultsToCanvas):

Source/WebKit/chromium:

Add support for reading from the composited version of a canvas.

* public/WebGraphicsContext3D.h:
* src/Extensions3DChromium.cpp:
(WebCore::Extensions3DChromium::paintFramebufferToCanvas):
* src/GraphicsContext3DChromium.cpp:
(WebCore::GraphicsContext3DInternal::GraphicsContext3DInternal):
(WebCore::GraphicsContext3DInternal::paintFramebufferToCanvas):
(WebCore::GraphicsContext3DInternal::paintRenderingResultsToCanvas):
(WebCore::GraphicsContext3DInternal::paintCompositedResultsToCanvas):
(WebCore::GraphicsContext3DInternal::paintRenderingResultsToImageData):
(WebCore::GraphicsContext3DInternal::reshape):
* src/GraphicsContext3DInternal.h:

TBR=commit-queue@webkit.org
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=93077