Add the plumbing that will carry a clipboard item from a chromoting client to a host.

remoting/proto/event.proto

Index: remoting/proto/event.proto
diff --git a/remoting/proto/event.proto b/remoting/proto/event.proto
index dcc2aaebea7d2dfeeb67fcca54608612886f631c..163eeefde3de0cf9293e5500bd8d0d177d0c0594 100644
--- a/remoting/proto/event.proto
+++ b/remoting/proto/event.proto
@@ -48,3 +48,16 @@ message MouseEvent {
   optional MouseButton button = 5;
   optional bool button_down = 6;
 }
+
+// Defines an event that sends clipboard data between peers.
+message ClipboardEvent {
+
+  // The type of the data being sent.
+  enum DataType {
+    DATA_TYPE_TEXT_UTF8 = 0;

[garykac, 2012/03/09 00:51:19]

Is the UTF8 suffix redundant or is the plan to support different text encodings
(SJIS, KOI8, Big5)?  Or is this just to allow alternate Unicode formats (like
UCS2)?

Supporting different text encodings doesn't seem worthwhile nor does supporting
UCS2 as an option (Japanese text requires 50% more storage with UTF8 vs UCS2,
but this isn't critical).

I would recommend using only UTF8 for text and naming this simply DATA_TYPE_TEXT
(with a comment noting that it's UTF8 encoded).

[simonmorris, 2012/03/09 00:53:24]

OK - I agree that we only want UTF-8.

+  }
+  required DataType dataType = 1;
+
+  // The data being sent.
+  required bytes data = 2;
+}