Fix mixed samples stencil clip

Fixes rendering bugs and nondeterminism in gm.

Before, mixed samples stencil clip would try to infer whether the draw
wanted co-centered sample locations from within GrGLGpu, which caused
various errors. This change reworks it so the draw itself can request
the co-centered sample locations when it knows it will need them.

Also reduces framebuffer binds by moving the code that enables
GL_FRAMEBUFFER_PROGRAMMABLE_SAMPLE_LOCATIONS into flushRenderTarget.

Review URL: https://codereview.chromium.org/1431593006

1 files changed, 5 insertions, 4 deletions

diff --git a/src/gpu/gl/GrGLRenderTarget.cpp b/src/gpu/gl/GrGLRenderTarget.cpp
index d4585f6402..2c15887259 100644
--- a/src/gpu/gl/GrGLRenderTarget.cpp
+++ b/src/gpu/gl/GrGLRenderTarget.cpp
@@ -34,10 +34,11 @@ GrGLRenderTarget::GrGLRenderTarget(GrGLGpu* gpu, const GrSurfaceDesc& desc, cons
 }
 
 void GrGLRenderTarget::init(const GrSurfaceDesc& desc, const IDDesc& idDesc) {
-    fRTFBOID                = idDesc.fRTFBOID;
-    fTexFBOID               = idDesc.fTexFBOID;
-    fMSColorRenderbufferID  = idDesc.fMSColorRenderbufferID;
-    fRTLifecycle            = idDesc.fLifeCycle;
+    fRTFBOID                       = idDesc.fRTFBOID;
+    fTexFBOID                      = idDesc.fTexFBOID;
+    fMSColorRenderbufferID         = idDesc.fMSColorRenderbufferID;
+    fRTLifecycle                   = idDesc.fLifeCycle;
+    fHasCoCenteredSamplesTimestamp = GrGpu::kExpiredTimestamp;
 
     fViewport.fLeft   = 0;
     fViewport.fBottom = 0;