--- a/devtools/shared/adb/test/adb.py
+++ b/devtools/shared/adb/test/adb.py
@@ -15,19 +15,27 @@ import SocketServer
 import sys
 import thread
 
 HOST = '127.0.0.1'
 PORT = 5037
 
 class ADBServer(SocketServer.BaseRequestHandler):
     def sendData(self, data):
-        self.request.send('OKAY')
-        self.request.send('%04x' % len(data))
-        self.request.send(data)
+        header = 'OKAY%04x' % len(data)
+        all_data = header + data
+        total_length = len(all_data)
+        sent_length = 0
+        # Make sure send all data to the client.
+        # Though the data length here is pretty small but sometimes when the
+        # client is on heavy load (e.g. MOZ_CHAOSMODE) we can't send the whole
+        # data at once.
+        while sent_length < total_length:
+            sent = self.request.send(all_data[sent_length:])
+            sent_length = sent_length + sent
 
     def handle(self):
         while True:
             data = self.request.recv(4096)
             if 'kill-server' in data:
                 def shutdown(server):
                     server.shutdown()
                     thread.exit()