Add operator* and operator safe-bool to sk_sp.

tests/RefCntTest.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkRefCnt.h"
 #include "SkThreadUtils.h"
 #include "SkTypes.h"
@@ skipping 146 matching lines @@
 
     Paint paint;
     REPORTER_ASSERT(reporter, paint.fEffect.get() == nullptr);
     REPORTER_ASSERT(reporter, !paint.get());
     check(reporter, 0, 0, 0, 0);
 
     paint.set(Create());
     check(reporter, 0, 0, 1, 0);
     REPORTER_ASSERT(reporter, paint.fEffect.get()->fRefCnt == 1);
 
+    if (paint.get()) {
+        REPORTER_ASSERT(reporter, true);
+    } else {
+        REPORTER_ASSERT(reporter, false);
+    }
+
     paint.set(nullptr);
     check(reporter, 0, 1, 1, 1);
 
+    if (paint.get()) {
+        REPORTER_ASSERT(reporter, false);
+    } else {
+        REPORTER_ASSERT(reporter, true);
+    }
+
     auto e = Create();
     REPORTER_ASSERT(reporter, sizeof(e) == sizeof(void*));
 
     check(reporter, 0, 1, 2, 1);
     paint.set(e);
     check(reporter, 1, 1, 2, 1);
     REPORTER_ASSERT(reporter, paint.fEffect.get()->fRefCnt == 2);
 
     Paint paint2;
     paint2.set(paint.get());
     check(reporter, 2, 1, 2, 1);
     REPORTER_ASSERT(reporter, paint.fEffect.get()->fRefCnt == 3);
 
-    delete paint.get()->method();
+    delete (*paint.get()).method();

[mtklein, 2016/03/02 20:05:10]

 // tests operator*

     check(reporter, 2, 1, 2, 1);
 
     paint.set(nullptr);
     e = nullptr;
     paint2.set(nullptr);
     check(reporter, 2, 4, 2, 2);
 
     reset_counters();
     {
         // Test convertible sk_sp assignment.
@@ skipping 46 matching lines @@
     baz = EffectImpl::Create();
     check(reporter, 0, 0, 1, 0);
     paint.set(baz);
     check(reporter, 1, 0, 1, 0);
     baz = nullptr;
     check(reporter, 1, 1, 1, 0);
     paint.set(nullptr);
     check(reporter, 1, 2, 1, 1);
 }