Don't create multiple WebRange objects for getting selection text.

content/renderer/render_frame_impl.cc

 // Copyright 2013 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 "content/renderer/render_frame_impl.h"
 
 #include <map>
 #include <string>
 
 #include "base/auto_reset.h"
@@ skipping 4039 matching lines @@
       // If current focused element is editable, we will send 100 more chars
       // before and after selection. It is for input method surrounding text
       // feature.
       if (location > kExtraCharsBeforeAndAfterSelection)
         offset = location - kExtraCharsBeforeAndAfterSelection;
       else
         offset = 0;
       length = location + length - offset + kExtraCharsBeforeAndAfterSelection;
       WebRange webrange = WebRange::fromDocumentRange(frame_, offset, length);
       if (!webrange.isNull())
-        text = WebRange::fromDocumentRange(
-            frame_, offset, length).toPlainText();
+        text = webrange.toPlainText();
     } else {
       offset = location;
       text = frame_->selectionAsText();
       // http://crbug.com/101435
       // In some case, frame->selectionAsText() returned text's length is not
       // equal to the length returned from webwidget()->caretOrSelectionRange().
       // So we have to set the range according to text.length().
       range.set_end(range.start() + text.length());
     }
   }
@@ skipping 194 matching lines @@
 
 #if defined(ENABLE_BROWSER_CDMS)
 RendererCdmManager* RenderFrameImpl::GetCdmManager() {
   if (!cdm_manager_)
     cdm_manager_ = new RendererCdmManager(this);
   return cdm_manager_;
 }
 #endif  // defined(ENABLE_BROWSER_CDMS)
 
 }  // namespace content