IPC::Message Refactoring: Move POSIX specific bits to PlatformFileAttachment

This change:

 * Gets rid of MessageAttachmentSet::owning_descriptors_ by moving
   the responsibility to PlatformFileAttachment, where owning_
   member variable is used to track the lifetime
 * Replaces MessageAttachmetnSet::Add*File() and TakePlatformFile()
   with platform agnostic AddAttachment() and GetAttachmentAt()
 * Repalces Message::ReadFile(), Write*File() with ReadAttachment()
   and WriteAttachmente(), which are also platform agnostic.

This also adds MessageAttachment::TakePlatformFile() virtual function,
which will be implemented by upcoming MojoHandleAttachment as well.

This is another preparation for introducing MojoHandleAttachment,
but it also simplifies Message and MessageAttachmentSet.

R=agl@chromium.org
TBR=mtomasz@chromium.org
BUG=448190

Review URL: https://codereview.chromium.org/883093003

Cr-Commit-Position: refs/heads/master@{#314047}

1 files changed, 6 insertions, 3 deletions

diff --git a/ipc/mojo/ipc_channel_mojo_unittest.cc b/ipc/mojo/ipc_channel_mojo_unittest.cc
index 47e72fc..6ebaa73 100644
--- a/ipc/mojo/ipc_channel_mojo_unittest.cc
+++ b/ipc/mojo/ipc_channel_mojo_unittest.cc
@@ -17,6 +17,7 @@
 
 #if defined(OS_POSIX)
 #include "base/file_descriptor_posix.h"
+#include "ipc/ipc_platform_file_attachment_posix.h"
 #endif
 
 namespace {
@@ -328,8 +329,9 @@ class ListenerThatExpectsFile : public IPC::Listener {
     PickleIterator iter(message);
 
     base::ScopedFD fd;
-    EXPECT_TRUE(message.ReadFile(&iter, &fd));
-    base::File file(fd.release());
+    scoped_refptr<IPC::MessageAttachment> attachment;
+    EXPECT_TRUE(message.ReadAttachment(&iter, &attachment));
+    base::File file(attachment->TakePlatformFile());
     std::string content(GetSendingFileContent().size(), ' ');
     file.Read(0, &content[0], content.size());
     EXPECT_EQ(content, GetSendingFileContent());
@@ -359,7 +361,8 @@ class ListenerThatExpectsFile : public IPC::Listener {
     file.Flush();
     IPC::Message* message = new IPC::Message(
         0, 2, IPC::Message::PRIORITY_NORMAL);
-    message->WriteFile(base::ScopedFD(file.TakePlatformFile()));
+    message->WriteAttachment(new IPC::internal::PlatformFileAttachment(
+        base::ScopedFD(file.TakePlatformFile())));
     ASSERT_TRUE(sender->Send(message));
   }