Revert of Make FrameSelection to hold non-canonicalized positions

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

Index: third_party/WebKit/Source/core/editing/FrameCaret.cpp
diff --git a/third_party/WebKit/Source/core/editing/FrameCaret.cpp b/third_party/WebKit/Source/core/editing/FrameCaret.cpp
index 640f161b6e3af20a571c37df626391730399aa5c..a69dbedbf67c7fc4c8ef97a7a564f5b93b9a9fa0 100644
--- a/third_party/WebKit/Source/core/editing/FrameCaret.cpp
+++ b/third_party/WebKit/Source/core/editing/FrameCaret.cpp
@@ -81,14 +81,20 @@
 }
 
 void FrameCaret::updateAppearance() {
-  DCHECK_GE(m_frame->document()->lifecycle().state(),
-            DocumentLifecycle::LayoutClean);
   // Paint a block cursor instead of a caret in overtype mode unless the caret
   // is at the end of a line (in this case the FrameSelection will paint a
   // blinking caret as usual).
-  const bool paintBlockCursor =
-      m_shouldShowBlockCursor && isActive() &&
-      !isLogicalEndOfLine(createVisiblePosition(caretPosition()));
+  bool paintBlockCursor = m_shouldShowBlockCursor && isActive();
+  if (paintBlockCursor) {
+    // TODO(editing-dev): Use of updateStyleAndLayoutIgnorePendingStylesheets
+    // needs to be audited.  see http://crbug.com/590369 for more details.
+    // In the long term, we should defer the update of the caret's appearance
+    // to prevent synchronous layout.
+    m_frame->document()->updateStyleAndLayoutIgnorePendingStylesheets();
+
+    if (isLogicalEndOfLine(createVisiblePosition(caretPosition())))
+      paintBlockCursor = false;
+  }
 
   bool shouldBlink = !paintBlockCursor && shouldBlinkCaret();
 
@@ -129,8 +135,7 @@
 
   m_caretVisibility = visibility;
 
-  if (visibility == CaretVisibility::Hidden)
-    stopCaretBlinkTimer();
+  updateAppearance();
   scheduleVisualUpdateForPaintInvalidationIfNeeded();
 }
 
@@ -143,9 +148,6 @@
 }
 
 void FrameCaret::updateStyleAndLayoutIfNeeded() {
-  DCHECK_GE(m_frame->document()->lifecycle().state(),
-            DocumentLifecycle::LayoutClean);
-  updateAppearance();
   bool shouldPaintCaret =
       m_shouldPaintCaret && isActive() &&
       m_caretVisibility == CaretVisibility::Visible &&
@@ -197,7 +199,10 @@
 
 void FrameCaret::setShouldShowBlockCursor(bool shouldShowBlockCursor) {
   m_shouldShowBlockCursor = shouldShowBlockCursor;
-  scheduleVisualUpdateForPaintInvalidationIfNeeded();
+
+  m_frame->document()->updateStyleAndLayoutIgnorePendingStylesheets();
+
+  updateAppearance();
 }
 
 bool FrameCaret::shouldPaintCaret(const LayoutBlock& block) const {