Coverity: Fix pass by value error in IMEInputEvent_Dev.

ppapi/cpp/dev/ime_input_event_dev.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ppapi/cpp/dev/ime_input_event_dev.h"
 
 #include "ppapi/cpp/instance.h"
 #include "ppapi/cpp/module.h"
 #include "ppapi/cpp/module_impl.h"
 #include "ppapi/cpp/var.h"
@@ skipping 34 matching lines @@
   if (is_ime_event) {
     Module::Get()->core()->AddRefResource(event.pp_resource());
     PassRefFromConstructor(event.pp_resource());
   }
 }
 
 IMEInputEvent_Dev::IMEInputEvent_Dev(
     const InstanceHandle& instance,
     PP_InputEvent_Type type,
     PP_TimeTicks time_stamp,
-    Var text,
+    const Var& text,
     const std::vector<uint32_t>& segment_offsets,
     int32_t target_segment,
     const std::pair<uint32_t, uint32_t>& selection) : InputEvent() {
   if (!has_interface<PPB_IMEInputEvent_Dev_0_2>())
     return;
   uint32_t dummy = 0;
   PassRefFromConstructor(get_interface<PPB_IMEInputEvent_Dev_0_2>()->Create(
       instance.pp_instance(), type, time_stamp, text.pp_var(),
       segment_offsets.empty() ? 0 : segment_offsets.size() - 1,
       segment_offsets.empty() ? &dummy : &segment_offsets[0],
@@ skipping 56 matching lines @@
   } else if (has_interface<PPB_IMEInputEvent_Dev_0_1>()) {
     get_interface<PPB_IMEInputEvent_Dev_0_1>()->GetSelection(pp_resource(),
                                                              &range.first,
                                                              &range.second);
   }
   return range;
 }
 
 
 }  // namespace pp