Fix missing flush in sending a SwitchTransport message.

Public review at: http://gwt-code-reviews.appspot.com/350803/show

Patch by: jat
Review by: rice


git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@7958 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/dev/core/src/com/google/gwt/dev/shell/BrowserChannel.java b/dev/core/src/com/google/gwt/dev/shell/BrowserChannel.java
index be5c3b3..e905589 100644
--- a/dev/core/src/com/google/gwt/dev/shell/BrowserChannel.java
+++ b/dev/core/src/com/google/gwt/dev/shell/BrowserChannel.java
@@ -1386,6 +1386,7 @@
       stream.writeByte(MessageType.SWITCH_TRANSPORT.getId());
       writeUtf8String(stream, transport);
       writeUtf8String(stream, transportArgs);
+      stream.flush();
     }
   }