remove Sk64 from public API, and start to remove usage internally

tests/Sk64Test.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "Test.h"
 #include "TestClassDef.h"
+#include "Sk64.h"
 #include "SkRandom.h"
 #include <math.h>
 
 struct BoolTable {
     int8_t  zero, pos, neg, toBool, sign;
 };
 
 static void bool_table_test(skiatest::Reporter* reporter,
                             const Sk64& a, const BoolTable& table)
 {
@@ skipping 65 matching lines @@
         REPORTER_ASSERT(reporter, c.get32() == aa + bb);
         c = a; c.add(-bb);
         REPORTER_ASSERT(reporter, c.get32() == aa - bb);
         c = a; c.add(b);
         REPORTER_ASSERT(reporter, c.get32() == aa + bb);
         c = a; c.sub(b);
         REPORTER_ASSERT(reporter, c.get32() == aa - bb);
     }
 
     for (i = 0; i < 1000; i++) {
-        rand.next64(&a); //a.fHi >>= 1; // avoid overflow
-        rand.next64(&b); //b.fHi >>= 1; // avoid overflow
+        a.set64(rand.next64());
+        b.set64(rand.next64());
 
         if (!(i & 3))   // want to explicitly test these cases
         {
             a.fLo = 0;
             b.fLo = 0;
         }
         else if (!(i & 7))  // want to explicitly test these cases
         {
             a.fHi = 0;
             b.fHi = 0;
@@ skipping 59 matching lines @@
         denom = wide.getSqrt();
         int32_t ck = (int32_t)sqrt((double)wide.getLongLong());
         int diff = denom - ck;
         REPORTER_ASSERT(reporter, SkAbs32(diff) <= 1);
     }
 }
 
 DEF_TEST(Sk64Test, reporter) {
     Sk64::UnitTestWithReporter(reporter);
 }