Ensure clean layout before calling plainText() (flat tree version)

third_party/WebKit/Source/core/frame/LocalFrame.cpp

Index: third_party/WebKit/Source/core/frame/LocalFrame.cpp
diff --git a/third_party/WebKit/Source/core/frame/LocalFrame.cpp b/third_party/WebKit/Source/core/frame/LocalFrame.cpp
index 21aa4571a02913c234e721802b7bf49d100121b4..14e447196f6d5f25649a2e48cb2ed202a6fe7259 100644
--- a/third_party/WebKit/Source/core/frame/LocalFrame.cpp
+++ b/third_party/WebKit/Source/core/frame/LocalFrame.cpp
@@ -673,6 +673,13 @@ String LocalFrame::selectedText() const
 
 String LocalFrame::selectedTextForClipboard() const
 {
+    if (!document())
+        return emptyString();
+
+    // TODO(xiaochengh): The use of updateStyleAndLayoutIgnorePendingStylesheets
+    // needs to be audited.  See http://crbug.com/590369 for more details.
+    document()->updateStyleAndLayoutIgnorePendingStylesheets();
+
     return selection().selectedTextForClipboard();
 }