Revert "Drop support for unused MSAA extensions"

This reverts commit 7df27465c4ecc8a4a0cdd95e9785c342903c2de9.

Reason for revert: experimental revert to see if this is the cause of the tree redness

Original change's description:
> Drop support for unused MSAA extensions
> 
> Bug: skia:
> Change-Id: I113b80e3f991f195155148625ceb29242ea82776
> Reviewed-on: https://skia-review.googlesource.com/101403
> Reviewed-by: Brian Salomon <bsalomon@google.com>
> Commit-Queue: Chris Dalton <csmartdalton@google.com>

TBR=bsalomon@google.com,csmartdalton@google.com,ethannicholas@google.com

Change-Id: I4fa4123e2d176bef88cd76a09a14053d9ac5809f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/101680
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/gpu/GrProgramDesc.cpp b/src/gpu/GrProgramDesc.cpp
index c3d61985de..9c0add66e6 100644
--- a/src/gpu/GrProgramDesc.cpp
+++ b/src/gpu/GrProgramDesc.cpp
@@ -169,6 +169,7 @@ bool GrProgramDesc::Build(GrProgramDesc* desc,
         desc->key().reset();
         return false;
     }
+    GrProcessor::RequiredFeatures requiredFeatures = primProc.requiredFeatures();
 
     for (int i = 0; i < pipeline.numFragmentProcessors(); ++i) {
         const GrFragmentProcessor& fp = pipeline.getFragmentProcessor(i);
@@ -176,6 +177,7 @@ bool GrProgramDesc::Build(GrProgramDesc* desc,
             desc->key().reset();
             return false;
         }
+        requiredFeatures |= fp.requiredFeatures();
     }
 
     const GrXferProcessor& xp = pipeline.getXferProcessor();
@@ -190,6 +192,7 @@ bool GrProgramDesc::Build(GrProgramDesc* desc,
         desc->key().reset();
         return false;
     }
+    requiredFeatures |= xp.requiredFeatures();
 
     // --------DO NOT MOVE HEADER ABOVE THIS LINE--------------------------------------------------
     // Because header is a pointer into the dynamic array, we can't push any new data into the key
@@ -201,6 +204,16 @@ bool GrProgramDesc::Build(GrProgramDesc* desc,
 
     GrRenderTargetProxy* proxy = pipeline.proxy();
 
+    if (requiredFeatures & GrProcessor::kSampleLocations_RequiredFeature) {
+        SkASSERT(pipeline.isHWAntialiasState());
+
+        GrRenderTarget* rt = pipeline.renderTarget();
+        header->fSamplePatternKey =
+            rt->renderTargetPriv().getMultisampleSpecs(pipeline).fUniqueID;
+    } else {
+        header->fSamplePatternKey = 0;
+    }
+
     header->fOutputSwizzle = shaderCaps.configOutputSwizzle(proxy->config()).asKey();
 
     header->fSnapVerticesToPixelCenters = pipeline.snapVerticesToPixelCenters();