Add support for persisting CompositionUnderlines in InputMethodController

third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.cpp

Index: third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.cpp
diff --git a/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.cpp b/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.cpp
index 866d02dfe99734e203c106c3f9c8b144b4f294f3..6541e8cf97bb436d33b789e162f5becffa63ad5c 100644
--- a/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.cpp
+++ b/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.cpp
@@ -644,13 +644,16 @@ void CompositeEditCommand::replaceTextInNode(Text* node,
                                              const String& replacementText) {
   // DeleteFromTextNodeCommand and InsertIntoTextNodeCommand are never
   // aborted.
-  applyCommandToComposite(
-      DeleteFromTextNodeCommand::create(node, offset, count),
-      ASSERT_NO_EDITING_ABORT);
+
+  // Insert must happen before delete to preserve markers correctly

[rlanday, 2017/01/03 21:07:03]

This is something that came up when I added a test case. There's some piece of
logic that sometimes replaced spaces with &nbsps; and the marker range was no
longer including the space because it was deleting the old space and adding the
new one (and ending up outside the marker range) instead of inserting first (so
the new space stays in the marker range).

+  // See algorithm in https://dom.spec.whatwg.org/#concept-cd-replace
   if (!replacementText.isEmpty())
     applyCommandToComposite(
         InsertIntoTextNodeCommand::create(node, offset, replacementText),
         ASSERT_NO_EDITING_ABORT);
+  applyCommandToComposite(DeleteFromTextNodeCommand::create(
+                              node, offset + replacementText.length(), count),
+                          ASSERT_NO_EDITING_ABORT);
 }
 
 Position CompositeEditCommand::replaceSelectedTextInNode(const String& text) {