Write to selection clipboard from setTimeout

This is so that in progress transactions aren't written to the
selection clipboard.

src/text-editor-component.coffee

@@ -435,12 +435,16 @@ TextEditorComponent = React.createClass
   # Listen for selection changes and store the currently selected text
   # in the selection clipboard. This is only applicable on Linux.
   trackSelectionClipboard: ->
-    @subscribe @props.editor.onDidChangeSelectionRange =>
+    timeoutId = null
+    writeSelectedTextToSelectionClipboard = =>
       if selectedText = @props.editor.getSelectedText()
         # This uses ipc.send instead of clipboard.writeText because
         # clipboard.writeText is a sync ipc call on Linux and that
         # will slow down selections.
         ipc.send('write-text-to-selection-clipboard', selectedText)
+    @subscribe @props.editor.onDidChangeSelectionRange =>
+      clearTimeout(timeoutId)
+      timeoutId = setTimeout(writeSelectedTextToSelectionClipboard)
 
   observeConfig: ->
     @subscribe atom.config.observe 'editor.useHardwareAcceleration', @setUseHardwareAcceleration