Workaround for clang bug http://llvm.org/PR28348.

webrtc/media/base/videoframe_unittest.h

 /*
  *  Copyright (c) 2004 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 1198 matching lines @@
     // Allocate a buffer with end page aligned.
     const int kPadToHeapSized = 16 * 1024 * 1024;
     std::unique_ptr<uint8_t[]> page_buffer(
         new uint8_t[((data_size + kPadToHeapSized + 4095) & ~4095)]);
     uint8_t* data_ptr = page_buffer.get();
     if (!data_ptr) {
       LOG(LS_WARNING) << "Failed to allocate memory for ValidateFrame test.";
       EXPECT_FALSE(expected_result);  // NULL is okay if failure was expected.
       return;
     }
-    data_ptr += kPadToHeapSized + (-(static_cast<int>(data_size)) & 4095);
+    // TODO(pbos): Remove kPad once http://llvm.org/PR28348 is fixed and the fix
+    // is rolled in.
+    volatile const int kPad = 4095;
+    data_ptr += kPadToHeapSized + (-(static_cast<int>(data_size)) & kPad);
     memcpy(data_ptr, sample, std::min(data_size, sample_size));
     for (int i = 0; i < repeat_; ++i) {
       EXPECT_EQ(expected_result, frame.Validate(fourcc, kWidth, kHeight,
                                                 data_ptr,
                                                 sample_size + size_adjust));
     }
   }
 
   // Test validate for I420 MJPG buffer.
   void ValidateMjpgI420() {
@@ skipping 600 matching lines @@
     target.reset(source->Copy());
     EXPECT_TRUE(IsEqual(*source, *target, 0));
     const T* const_source = source.get();
     EXPECT_EQ(const_source->video_frame_buffer(), target->video_frame_buffer());
   }
 
   int repeat_;
 };
 
 #endif  // WEBRTC_MEDIA_BASE_VIDEOFRAME_UNITTEST_H_