Rewrite DocumentMarkerController to use SynchronousMutationObserver

third_party/WebKit/Source/core/dom/Document.cpp

Index: third_party/WebKit/Source/core/dom/Document.cpp
diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index 13c590feef862ddb9edb151d758d49a7525602e5..ef0146f91b972f9fadaa680e81237c8d3a2faa3c 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -4268,16 +4268,11 @@ void Document::nodeWillBeRemoved(Node& n) {
 void Document::didInsertText(Node* text, unsigned offset, unsigned length) {
   for (Range* range : m_ranges)
     range->didInsertText(text, offset, length);
-
-  m_markers->shiftMarkers(text, offset, length);
 }
 
 void Document::didRemoveText(Node* text, unsigned offset, unsigned length) {
   for (Range* range : m_ranges)
     range->didRemoveText(text, offset, length);
-
-  m_markers->removeMarkers(text, offset, length);
-  m_markers->shiftMarkers(text, offset + length, 0 - length);
 }
 
 void Document::didMergeTextNodes(const Text& mergedNode,