Require generation to be GLSL 3.30 in GrShaderCaps::supportsSkSLES3().

Real devices exist which support derivatives, non-square matrices, and
unsigned integers, but do not support all of ES3. On our tree,
ChromeOS-Clang-Sparky360-GPU-IntelUHDGraphics605-x86_64 meets this
criteria.

Change-Id: I6ae438c8cde291ca834f61700463a2df55705cb0
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/441077
Commit-Queue: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>

src/gpu/GrShaderCaps.h

@@ -101,7 +101,8 @@ public:
      * SkSL ES3 requires support for derivatives, nonsquare matrices and bitwise integer operations.
      */
     bool supportsSkSLES3() const {
-        return fShaderDerivativeSupport && fNonsquareMatrixSupport && fIntegerSupport;
+        return fShaderDerivativeSupport && fNonsquareMatrixSupport && fIntegerSupport &&
+               fGLSLGeneration >= k330_GrGLSLGeneration;
     }
 
     // SkSL only.