linux_aura: Fix PRIMARY selection in the content area.

content/browser/renderer_host/render_widget_host_view_aura.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 "content/browser/renderer_host/render_widget_host_view_aura.h"
 
 #include "base/auto_reset.h"
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/callback_helpers.h"
@@ skipping 1023 matching lines @@
 }
 
 void RenderWidgetHostViewAura::SelectionChanged(const base::string16& text,
                                                 size_t offset,
                                                 const gfx::Range& range) {
   RenderWidgetHostViewBase::SelectionChanged(text, offset, range);
 
 #if defined(USE_X11) && !defined(OS_CHROMEOS)
   if (text.empty() || range.is_empty())
     return;
+  size_t pos = range.GetMin() - offset;
+  size_t n = range.length();
+
+  DCHECK(pos + n <= text.length()) << "The text can not fully cover range.";
+  if (pos >= text.length()) {
+    NOTREACHED() << "The text can not cover range.";
+    return;
+  }
 
   // Set the CLIPBOARD_TYPE_SELECTION to the ui::Clipboard.
   ui::ScopedClipboardWriter clipboard_writer(
       ui::Clipboard::GetForCurrentThread(),
       ui::CLIPBOARD_TYPE_SELECTION);
-  clipboard_writer.WriteText(text);
+  clipboard_writer.WriteText(text.substr(pos, n));
 #endif  // defined(USE_X11) && !defined(OS_CHROMEOS)
 }
 
 void RenderWidgetHostViewAura::SelectionBoundsChanged(
     const ViewHostMsg_SelectionBounds_Params& params) {
   if (selection_anchor_rect_ == params.anchor_rect &&
       selection_focus_rect_ == params.focus_rect)
     return;
 
   selection_anchor_rect_ = params.anchor_rect;
@@ skipping 2535 matching lines @@
     RenderWidgetHost* widget) {
   return new RenderWidgetHostViewAura(widget);
 }
 
 // static
 void RenderWidgetHostViewPort::GetDefaultScreenInfo(WebScreenInfo* results) {
   GetScreenInfoForWindow(results, NULL);
 }
 
 }  // namespace content