Revert https://codereview.chromium.org/1291903002 (protobuf roll).

third_party/protobuf/src/google/protobuf/metadata.h

Index: third_party/protobuf/src/google/protobuf/metadata.h
diff --git a/third_party/protobuf/src/google/protobuf/metadata.h b/third_party/protobuf/src/google/protobuf/metadata.h
deleted file mode 100644
index 85065f01651b362ef915ea8cfb584c64a9497fbb..0000000000000000000000000000000000000000
--- a/third_party/protobuf/src/google/protobuf/metadata.h
+++ /dev/null
@@ -1,163 +0,0 @@
-// Protocol Buffers - Google's data interchange format
-// Copyright 2008 Google Inc.  All rights reserved.
-// https://developers.google.com/protocol-buffers/
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-// This header file defines an internal class that encapsulates internal message
-// metadata (Unknown-field set, Arena pointer, ...) and allows its
-// representation to be made more space-efficient via various optimizations.
-//
-// Note that this is distinct from google::protobuf::Metadata, which encapsulates
-// Descriptor and Reflection pointers.
-
-#ifndef GOOGLE_PROTOBUF_METADATA_H__
-#define GOOGLE_PROTOBUF_METADATA_H__
-
-#include <google/protobuf/stubs/common.h>
-#include <google/protobuf/arena.h>
-#include <google/protobuf/unknown_field_set.h>
-
-namespace google {
-namespace protobuf {
-namespace internal {
-
-// This is the representation for messages that support arena allocation. It
-// uses a tagged pointer to either store the Arena pointer, if there are no
-// unknown fields, or a pointer to a block of memory with both the Arena pointer
-// and the UnknownFieldSet, if there are unknown fields. This optimization
-// allows for "zero-overhead" storage of the Arena pointer, relative to the
-// above baseline implementation.
-//
-// The tagged pointer uses the LSB to disambiguate cases, and uses bit 0 == 0 to
-// indicate an arena pointer and bit 0 == 1 to indicate a UFS+Arena-container
-// pointer.
-class LIBPROTOBUF_EXPORT InternalMetadataWithArena {
- public:
-  InternalMetadataWithArena() : ptr_(NULL) {}
-  explicit InternalMetadataWithArena(Arena* arena);
-
-  ~InternalMetadataWithArena() {
-    if (have_unknown_fields() && arena() == NULL) {
-      delete PtrValue<Container>();
-    }
-    ptr_ = NULL;
-  }
-
-  inline const UnknownFieldSet& unknown_fields() const
-      GOOGLE_ATTRIBUTE_ALWAYS_INLINE {
-    if (GOOGLE_PREDICT_FALSE(have_unknown_fields())) {
-      return PtrValue<Container>()->unknown_fields_;
-    } else {
-      return *UnknownFieldSet::default_instance();
-    }
-  }
-
-  inline UnknownFieldSet* mutable_unknown_fields() GOOGLE_ATTRIBUTE_ALWAYS_INLINE {
-    if (GOOGLE_PREDICT_TRUE(have_unknown_fields())) {
-      return &PtrValue<Container>()->unknown_fields_;
-    } else {
-      return mutable_unknown_fields_slow();
-    }
-  }
-
-  inline Arena* arena() const GOOGLE_ATTRIBUTE_ALWAYS_INLINE {
-    if (GOOGLE_PREDICT_FALSE(have_unknown_fields())) {
-      return PtrValue<Container>()->arena_;
-    } else {
-      return PtrValue<Arena>();
-    }
-  }
-
-  inline bool have_unknown_fields() const GOOGLE_ATTRIBUTE_ALWAYS_INLINE {
-    return PtrTag() == kTagContainer;
-  }
-
-  inline void Swap(InternalMetadataWithArena* other) GOOGLE_ATTRIBUTE_ALWAYS_INLINE {
-    // Semantics here are that we swap only the unknown fields, not the arena
-    // pointer. We cannot simply swap ptr_ with other->ptr_ because we need to
-    // maintain our own arena ptr. Also, our ptr_ and other's ptr_ may be in
-    // different states (direct arena pointer vs. container with UFS) so we
-    // cannot simply swap ptr_ and then restore the arena pointers. We reuse
-    // UFS's swap implementation instead.
-    if (have_unknown_fields() || other->have_unknown_fields()) {
-      mutable_unknown_fields()->Swap(other->mutable_unknown_fields());
-    }
-  }
-
-  inline void* raw_arena_ptr() const GOOGLE_ATTRIBUTE_ALWAYS_INLINE {
-    return ptr_;
-  }
-
- private:
-  void* ptr_;
-
-  // Tagged pointer implementation.
-  enum {
-    // ptr_ is an Arena*.
-    kTagArena = 0,
-    // ptr_ is a Container*.
-    kTagContainer = 1,
-  };
-  static const intptr_t kPtrTagMask = 1;
-  static const intptr_t kPtrValueMask = ~kPtrTagMask;
-
-  // Accessors for pointer tag and pointer value.
-  inline int PtrTag() const GOOGLE_ATTRIBUTE_ALWAYS_INLINE {
-    return reinterpret_cast<intptr_t>(ptr_) & kPtrTagMask;
-  }
-
-  template<typename T> T* PtrValue() const {
-    return reinterpret_cast<T*>(
-        reinterpret_cast<intptr_t>(ptr_) & kPtrValueMask);
-  }
-
-  // If ptr_'s tag is kTagContainer, it points to an instance of this struct.
-  struct Container {
-    UnknownFieldSet unknown_fields_;
-    Arena* arena_;
-  };
-
-  UnknownFieldSet* mutable_unknown_fields_slow() GOOGLE_ATTRIBUTE_NOINLINE {
-    Arena* my_arena = arena();
-    Container* container = Arena::Create<Container>(my_arena);
-    ptr_ = reinterpret_cast<void*>(
-        reinterpret_cast<intptr_t>(container) | kTagContainer);
-    container->arena_ = my_arena;
-    return &(container->unknown_fields_);
-  }
-};
-
-// Temporary compatibility typedef. Remove once this is released in components
-// and upb CL is submitted.
-typedef InternalMetadataWithArena InternalMetadata;
-
-}  // namespace internal
-}  // namespace protobuf
-
-}  // namespace google
-#endif  // GOOGLE_PROTOBUF_METADATA_H__