Add support for persisting CompositionUnderlines in InputMethodController

third_party/WebKit/Source/core/editing/CompositionUnderline.cpp

Index: third_party/WebKit/Source/core/editing/CompositionUnderline.cpp
diff --git a/third_party/WebKit/Source/core/editing/CompositionUnderline.cpp b/third_party/WebKit/Source/core/editing/CompositionUnderline.cpp
index e404879b86ccb7b461d896f3eaeda749d8783b57..846b67b1f886c9ffa5494adbefcbf3c59241f6f1 100644
--- a/third_party/WebKit/Source/core/editing/CompositionUnderline.cpp
+++ b/third_party/WebKit/Source/core/editing/CompositionUnderline.cpp
@@ -10,8 +10,12 @@ CompositionUnderline::CompositionUnderline(unsigned startOffset,
                                            unsigned endOffset,
                                            const Color& color,
                                            bool thick,
-                                           const Color& backgroundColor)
-    : m_color(color), m_thick(thick), m_backgroundColor(backgroundColor) {
+                                           const Color& backgroundColor,
+                                           bool persist)
+    : m_color(color),
+      m_thick(thick),
+      m_backgroundColor(backgroundColor),
+      m_persist(persist) {
   // Sanitize offsets by ensuring a valid range corresponding to the last
   // possible position.
   // TODO(wkorman): Consider replacing with DCHECK_LT(startOffset, endOffset).