mac: Delete more 10.5-only code

webkit/plugins/npapi/webplugin_delegate_impl_mac.mm

 // 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.
 
 #import <Cocoa/Cocoa.h>
 #import <QuartzCore/QuartzCore.h>
 
 #include "webkit/plugins/npapi/webplugin_delegate_impl.h"
 
 #include <string>
@@ skipping 942 matching lines @@
           base::TimeDelta::FromMilliseconds(kCoreAnimationRedrawPeriodMs),
           this, &WebPluginDelegateImpl::DrawLayerInSurface);
     } else if (!plugin_visible) {
       redraw_timer_->Stop();
     }
   }
 }
 
 void WebPluginDelegateImpl::StartIme() {
   // Currently the plugin IME implementation only works on 10.6.
-  if (instance()->event_model() != NPEventModelCocoa ||
-      base::mac::IsOSLeopardOrEarlier()) {
+  if (instance()->event_model() != NPEventModelCocoa)
     return;
-  }
   if (ime_enabled_)
     return;
   ime_enabled_ = true;
   plugin_->StartIme();
 }
 
 #pragma mark -
 #pragma mark Core Animation Support
 
 void WebPluginDelegateImpl::DrawLayerInSurface() {
@@ skipping 113 matching lines @@
   HIPoint mouse_location;
   HIGetMousePosition(kHICoordSpaceScreenPixel, NULL, &mouse_location);
   np_event.where.h = mouse_location.x;
   np_event.where.v = mouse_location.y;
   instance()->NPP_HandleEvent(&np_event);
 }
 #endif  // !NP_NO_CARBON
 
 }  // namespace npapi
 }  // namespace webkit