Revert "Revert "Add integer texture support.""

This reverts commit 9c7edb8311409a141b0dc1d5e480c68c629f1997.

Fixes ASAN errors

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4736

Change-Id: I1b1dae754d357b01da7169c8e7c59d7d8d8a10f6
Reviewed-on: https://skia-review.googlesource.com/4736
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/src/sksl/SkSLContext.h b/src/sksl/SkSLContext.h
index dc41c6d..80ad7fb 100644
--- a/src/sksl/SkSLContext.h
+++ b/src/sksl/SkSLContext.h
@@ -78,6 +78,8 @@
     , fSampler1DArrayShadow_Type(new Type("sampler1DArrayShadow"))
     , fSampler2DArrayShadow_Type(new Type("sampler2DArrayShadow"))
     , fSamplerCubeArrayShadow_Type(new Type("samplerCubeArrayShadow"))
+    // Related to below FIXME, gsampler*s don't currently expand to cover integer case.
+    , fISampler2D_Type(new Type("isampler2D", SpvDim2D, false, false, false, true))
     // FIXME figure out what we're supposed to do with the gsampler et al. types)
     , fGSampler1D_Type(new Type("$gsampler1D", static_type(*fSampler1D_Type)))
     , fGSampler2D_Type(new Type("$gsampler2D", static_type(*fSampler2D_Type)))
@@ -193,6 +195,8 @@
     const std::unique_ptr<Type> fSampler2DArrayShadow_Type;
     const std::unique_ptr<Type> fSamplerCubeArrayShadow_Type;
 
+    const std::unique_ptr<Type> fISampler2D_Type;
+
     const std::unique_ptr<Type> fGSampler1D_Type;
     const std::unique_ptr<Type> fGSampler2D_Type;
     const std::unique_ptr<Type> fGSampler3D_Type;