[mojo-edk] Keep old wire format and semantics on Android.

mojo/edk/system/channel.h

 // Copyright 2016 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.
 
 #ifndef MOJO_EDK_SYSTEM_CHANNEL_H_
 #define MOJO_EDK_SYSTEM_CHANNEL_H_
 
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
@@ skipping 27 matching lines @@
         // A control message containing handles to echo back.
         HANDLES_SENT,
         // A control message containing handles that can now be closed.
         HANDLES_SENT_ACK,
 #endif
       };
 
       // Message size in bytes, including the header.
       uint32_t num_bytes;
 
-#if defined(OS_CHROMEOS)
-      // Old message wire format for ChromeOS.
+#if defined(OS_CHROMEOS) || defined(OS_ANDROID)
+      // Old message wire format for ChromeOS and Android.
       // Number of attached handles.
       uint16_t num_handles;
 
       MessageType message_type;
 #else
       // Total size of header, including extra header data (i.e. HANDLEs on
       // windows).
       uint16_t num_header_bytes;
 
       // Number of attached handles. May be less than the reserved handle
       // storage size in this message on platforms that serialise handles as
       // data (i.e. HANDLEs on Windows, Mach ports on OSX).
       uint16_t num_handles;
 
       MessageType message_type;
 
       char padding[6];
-#endif  // defined(OS_CHROMEOS)
+#endif  // defined(OS_CHROMEOS) || defined(OS_ANDROID)
     };
 #pragma pack(pop)
 
     // Allocates and owns a buffer for message data with enough capacity for
     // |payload_size| bytes plus a header, plus |max_handles| platform handles.
     Message(size_t payload_size,
             size_t max_handles,
             Header::MessageType message_type = Header::MessageType::NORMAL);
 
     ~Message();
 
     // Constructs a Message from serialized message data.
     static MessagePtr Deserialize(const void* data, size_t data_num_bytes);
 
     const void* data() const { return data_; }
     size_t data_num_bytes() const { return size_; }
 
-#if defined(OS_CHROMEOS)
+#if defined(OS_CHROMEOS) || defined(OS_ANDROID)
     void* mutable_payload() { return static_cast<void*>(header_ + 1); }
     const void* payload() const {
       return static_cast<const void*>(header_ + 1);
     }
     size_t payload_size() const;
 #else
     const void* extra_header() const { return data_ + sizeof(Header); }
     void* mutable_extra_header() { return data_ + sizeof(Header); }
     size_t extra_header_size() const {
       return header_->num_header_bytes - sizeof(Header);
     }
 
     void* mutable_payload() { return data_ + header_->num_header_bytes; }
     const void* payload() const { return data_ + header_->num_header_bytes; }
     size_t payload_size() const;
-#endif  // defined(OS_CHROMEOS)
+#endif  // defined(OS_CHROMEOS) || defined(OS_ANDROID)
 
     size_t num_handles() const { return header_->num_handles; }
     bool has_handles() const { return header_->num_handles > 0; }
     PlatformHandle* handles();
 #if defined(OS_MACOSX) && !defined(OS_IOS)
     bool has_mach_ports() const;
 #endif
 
     // Note: SetHandles() and TakeHandles() invalidate any previous value of
     // handles().
@@ skipping 120 matching lines @@
   Delegate* delegate_;
   const scoped_ptr<ReadBuffer> read_buffer_;
 
   DISALLOW_COPY_AND_ASSIGN(Channel);
 };
 
 }  // namespace edk
 }  // namespace mojo
 
 #endif  // MOJO_EDK_SYSTEM_CHANNEL_H_