Implement support for mixed sampled render targets

Adds a new FBO type kStencil_MSFBOType that is selected whenever
NV_framebuffer_mixed_samples extension is available.  In this new
FBO type a non-msaa color buffer is created with a multisampled
stencil buffer attachment.

Replaces numSamples() with separate numColorSamples and numStencilSamples
methods in RenderTarget.

In mixed samples mode non-MSAA codepaths are used to draw simple shapes,
while NVPR-rendered paths and text are rendered with a multisampled
stencil.

BUG=skia:3177

Review URL: https://codereview.chromium.org/1001503002

1 files changed, 2 insertions, 2 deletions

diff --git a/src/core/SkMultiPictureDraw.cpp b/src/core/SkMultiPictureDraw.cpp
index 7cdab7300c..22fd05fb08 100644
--- a/src/core/SkMultiPictureDraw.cpp
+++ b/src/core/SkMultiPictureDraw.cpp
@@ -141,7 +141,7 @@ void SkMultiPictureDraw::draw(bool flush) {
             GrLayerHoister::FindLayersToAtlas(context, data.fPicture, initialMatrix,
                                               clipBounds,
                                               &atlasedNeedRendering, &atlasedRecycled,
-                                              rt->numSamples());
+                                              rt->numColorSamples());
         }
     }
 
@@ -174,7 +174,7 @@ void SkMultiPictureDraw::draw(bool flush) {
             // layers in the 'recycled' list since they have already been drawn.
             GrLayerHoister::FindLayersToHoist(context, picture, initialMatrix,
                                               clipBounds, &needRendering, &recycled,
-                                              rt->numSamples());
+                                              rt->numColorSamples());
 
             GrLayerHoister::DrawLayers(context, needRendering);