Switch uses of SkChecksum::Compute to Murmur3.

src/gpu/GrProgramDesc.h

Index: src/gpu/GrProgramDesc.h
diff --git a/src/gpu/GrProgramDesc.h b/src/gpu/GrProgramDesc.h
index 05b52cc7cd7dfaa948854487e90101ea382fd58d..15106305fa63500114e87cdb30606f6c76a246d0 100644
--- a/src/gpu/GrProgramDesc.h
+++ b/src/gpu/GrProgramDesc.h
@@ -107,8 +107,8 @@ protected:
         *(this->atOffset<uint32_t, GrProgramDesc::kLengthOffset>()) = SkToU32(keyLength);
 
         uint32_t* checksum = this->atOffset<uint32_t, GrProgramDesc::kChecksumOffset>();
-        *checksum = 0;
-        *checksum = SkChecksum::Compute(reinterpret_cast<uint32_t*>(fKey.begin()), keyLength);
+        *checksum = 0;  // We'll hash through these bytes, so make sure they're initialized.
+        *checksum = SkChecksum::Murmur3(fKey.begin(), keyLength);
     }
 
     // The key, stored in fKey, is composed of four parts: