IPC: Add attachment brokering support to the message header.

ipc/ipc_channel.cc

Index: ipc/ipc_channel.cc
diff --git a/ipc/ipc_channel.cc b/ipc/ipc_channel.cc
index ac09c5ab1ef1d00b31c4f3a2e7b0a260673dbfbe..a495665d6f37cacaa71b0b73b59399683324049f 100644
--- a/ipc/ipc_channel.cc
+++ b/ipc/ipc_channel.cc
@@ -41,4 +41,29 @@ std::string Channel::GenerateUniqueRandomChannelID() {
       base::RandInt(0, std::numeric_limits<int32>::max()));
 }
 
+Channel::OutputElement::OutputElement(Message* message)
+    : message_(message), buffer_(nullptr), length_(0) {}
+
+Channel::OutputElement::OutputElement(const char* buffer, size_t length)
+    : message_(nullptr), buffer_(buffer), length_(length) {}
+
+Channel::OutputElement::~OutputElement() {
+  if (message_)

[Tom Sepez, 2015/08/17 18:29:39]

no need to test before delete.  just delete them.
You might consider using a scoped_ptr here instead to indicate ownership.

[erikchen, 2015/08/18 05:59:46]

Done on both counts. 

+    delete message_;
+  if (buffer_)
+    delete buffer_;
+}
+
+size_t Channel::OutputElement::size() {
+  if (message_)
+    return message_->size();
+  return length_;
+}
+
+const void* Channel::OutputElement::data() {
+  if (message_)
+    return message_->data();
+  return buffer_;
+}
+
 }  // namespace IPC