Bitmap transport

chrome/common/ipc_maybe.h

Index: chrome/common/ipc_maybe.h
diff --git a/chrome/common/ipc_maybe.h b/chrome/common/ipc_maybe.h
new file mode 100644
index 0000000000000000000000000000000000000000..de45dc02b43b67c0c28355130e1bbf8d33d1c842
--- /dev/null
+++ b/chrome/common/ipc_maybe.h
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+#ifndef CHROME_COMMON_MAYBE_H_
+#define CHROME_COMMON_MAYBE_H_
+
+namespace IPC {
+
+// The Maybe type can be used to avoid serialising a type when it's invalid.
+// This is most useful in conjunction with FileDescriptor, as there's no
+// possible invalid value which can be serialised (one can type to use -1, but
+// the IPC channel will fail). It may also be useful if the invalid value is
+// otherwise expensive to serialise.
+template<typename A>
+struct Maybe {
+  bool valid;
+  A value;
+};
+
+}  // namespace IPC
+
+#endif  // CHROME_COMMON_MAYBE_H_