Revert "libmojo: Uprev the library to r456626 from Chromium"

This reverts commit 8ac9103e05b66812c25348943383f9365d1ce3e0.

Reason for revert: Broke the mac_sdk
Exempt-From-Owner-Approval: Fixing mac_sdk

Change-Id: I0b74d1abaa66933a93fd6f82ff018e8948c1204e

1 files changed, 44 insertions, 15 deletions

diff --git a/ipc/ipc_channel_handle.h b/ipc/ipc_channel_handle.h
index ef31b84..2e9dc3e 100644
--- a/ipc/ipc_channel_handle.h
+++ b/ipc/ipc_channel_handle.h
@@ -10,31 +10,60 @@
 #include "build/build_config.h"
 #include "mojo/public/cpp/system/message_pipe.h"
 
-#if defined(OS_NACL_SFI)
+#if defined(OS_POSIX)
 #include "base/file_descriptor_posix.h"
-#endif  // defined (OS_NACL_SFI)
+#elif defined(OS_WIN)
+#include <windows.h>
+#endif  // defined (OS_WIN)
 
-namespace IPC {
+// On Windows, any process can create an IPC channel and others can fetch
+// it by name.  We pass around the channel names over IPC.
+// On Windows the initialization of ChannelHandle with an existing pipe
+// handle is provided for convenience.
+// NOTE: A ChannelHandle with a pipe handle Will NOT be marshalled over IPC.
 
-// Note that serialization for this object is defined in the ParamTraits
-// template specialization in ipc_message_utils.h.
-#if defined(OS_NACL_SFI)
-struct ChannelHandle {
-  ChannelHandle() {}
-  explicit ChannelHandle(const base::FileDescriptor& s) : socket(s) {}
+// On POSIX, we instead pass around handles to channel endpoints via IPC.
+// When it's time to IPC a new channel endpoint around, we send both the
+// channel name as well as a base::FileDescriptor, which is itself a special
+// type that knows how to copy a socket endpoint over IPC.
+//
+// In sum, this data structure can be used to pass channel information by name
+// in both Windows and Posix. When passing a handle to a channel over IPC,
+// use this data structure only for POSIX.
+
+namespace IPC {
 
-  base::FileDescriptor socket;
-};
-#else
 struct ChannelHandle {
+  // Note that serialization for this object is defined in the ParamTraits
+  // template specialization in ipc_message_utils.h.
   ChannelHandle() {}
+  // The name that is passed in should be an absolute path for Posix.
+  // Otherwise there may be a problem in IPC communication between
+  // processes with different working directories.
+  ChannelHandle(const std::string& n) : name(n) {}
+  ChannelHandle(const char* n) : name(n) {}
+#if defined(OS_WIN)
+  explicit ChannelHandle(HANDLE h) : pipe(h) {}
+#elif defined(OS_POSIX)
+  ChannelHandle(const std::string& n, const base::FileDescriptor& s)
+      : name(n), socket(s) {}
+#endif  // defined(OS_POSIX)
   ChannelHandle(mojo::MessagePipeHandle h) : mojo_handle(h) {}
 
-  bool is_mojo_channel_handle() const { return mojo_handle.is_valid(); }
-
+  std::string name;
+#if defined(OS_POSIX)
+  base::FileDescriptor socket;
+#elif defined(OS_WIN)
+  // A simple container to automatically initialize pipe handle
+  struct PipeHandle {
+    PipeHandle() : handle(NULL) {}
+    PipeHandle(HANDLE h) : handle(h) {}
+    HANDLE handle;
+  };
+  PipeHandle pipe;
+#endif  // defined (OS_WIN)
   mojo::MessagePipeHandle mojo_handle;
 };
-#endif  // defined(OS_NACL_SFI)
 
 }  // namespace IPC