[iOS/ARC] Fix a violation of ODR in base::BindBlock under ARC.

base/mac/bind_objc_block_unittest.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "base/mac/bind_objc_block.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/callback_helpers.h"
+#include "build/build_config.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "testing/gtest_mac.h"
 
-// See bind_objc_block_unittest_arc.mm for why this is necessary. Remove once
-// gyp support is dropped.
-void BindObjcBlockUnittestArcLinkerWorkaround();
+#if defined(OS_IOS)
+#include "base/ios/weak_nsobject.h"
+#include "base/mac/scoped_nsautorelease_pool.h"
+#endif
 
 namespace {
 
-TEST(BindObjcBlockTest, EnableARCTests) {
-  BindObjcBlockUnittestArcLinkerWorkaround();
-}
-
 TEST(BindObjcBlockTest, TestScopedClosureRunnerExitScope) {
   int run_count = 0;
   int* ptr = &run_count;
   {
     base::ScopedClosureRunner runner(base::BindBlock(^{
         (*ptr)++;
     }));
     EXPECT_EQ(0, run_count);
   }
   EXPECT_EQ(1, run_count);
@@ skipping 63 matching lines @@
       base::BindBlock(^(int a, int b, const std::string& c,
                         const std::string& d, int e, const std::string& f) {
           *ptr = c + d + f;
           *ptr2 = a + b + e;
       });
   c.Run(1, 2, "infinite", "improbability", 3, "drive");
   EXPECT_EQ(result1, "infiniteimprobabilitydrive");
   EXPECT_EQ(result2, 6);
 }
 
+#if defined(OS_IOS)
+
+TEST(BindObjcBlockTest, TestBlockReleased) {
+  base::WeakNSObject<NSObject> weak_nsobject;
+  {
+    base::mac::ScopedNSAutoreleasePool autorelease_pool;
+    NSObject* nsobject = [[[NSObject alloc] init] autorelease];
+    weak_nsobject.reset(nsobject);
+
+    auto callback = base::BindBlock(^{
+      [nsobject description];
+    });
+  }
+  EXPECT_NSEQ(nil, weak_nsobject);
+}
+
+#endif
+
 }  // namespace