Reviewed by James Robinson.

        [Chromium] Minimize uploads in canvas 2d mixed mode rendering
        https://bugs.webkit.org/show_bug.cgi?id=45476

        No new tests - change is for performance, logic fixes only apparent when running hardware acceleration.

        - Enumeration values fixed, "CavasWillDraw" -> "CanvasDidDraw".
        - markDirtyRect() plumbed through GraphicsContext to PlatformContextSkia.
        - Texture::updateSubRect() added to allow uploading only a dirty rect.
        - Logic fix in ImageBuffer::draw(), caused canvas to canvas copies to be incorrect.

        * html/canvas/CanvasRenderingContext2D.cpp:
        (WebCore::CanvasRenderingContext2D::setAllAttributesToDefault):
        (WebCore::CanvasRenderingContext2D::strokeRect):
        (WebCore::CanvasRenderingContext2D::drawImage):
        (WebCore::CanvasRenderingContext2D::didDraw):
          - Logic fix for drawingContext()->markDirtyRect() call.
        (WebCore::CanvasRenderingContext2D::putImageData):
        (WebCore::CanvasRenderingContext2D::drawTextInternal):
          - Logic fix for calls to "didDraw()", use peer method first.
        * html/canvas/CanvasRenderingContext2D.h:
        * platform/graphics/GraphicsContext.cpp:
        (WebCore::GraphicsContext::drawImageBuffer):
        (WebCore::GraphicsContext::markDirtyRect):
        * platform/graphics/GraphicsContext.h:
        * platform/graphics/gpu/Texture.cpp:
        (WebCore::Texture::create):
        (WebCore::Texture::load):
        (WebCore::Texture::updateSubRect):
        * platform/graphics/gpu/Texture.h:
        * platform/graphics/gpu/TilingData.h:
        (WebCore::TilingData::borderTexels):
        * platform/graphics/skia/GraphicsContextSkia.cpp:
        (WebCore::GraphicsContext::clipConvexPolygon):
        (WebCore::GraphicsContext::markDirtyRect):
        * platform/graphics/skia/ImageBufferSkia.cpp:
        (WebCore::ImageBuffer::draw):
        * platform/graphics/skia/PlatformContextSkia.cpp:
        (WebCore::PlatformContextSkia::State::cloneInheritedProperties):
        (WebCore::PlatformContextSkia::drawRect):
        (WebCore::PlatformContextSkia::setFillColor):
        (WebCore::PlatformContextSkia::setStrokeColor):
        (WebCore::PlatformContextSkia::markDirtyRect):
        (WebCore::PlatformContextSkia::uploadSoftwareToHardware):
        * platform/graphics/skia/PlatformContextSkia.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@67123 268f45cc-cd09-0410-ab3c-d52691b4dbfc