[Editing] Introduce |EditCommandComposition::willUn/Reapply()| in prepare for 'beforeinput' (2/3)

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 8e9f33a1e1d1e1348aee20a445f9137a3502cd4a..ee81dce271d7319aab59e5652f6a218db8f031a0 100644
--- a/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.cpp
+++ b/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.cpp
@@ -105,11 +105,14 @@ bool EditCommandComposition::belongsTo(const LocalFrame& frame) const {
   return m_document->frame() == &frame;
 }
 
-void EditCommandComposition::unapply() {
+void EditCommandComposition::unapply(EditCommandSource source) {
   DCHECK(m_document);
   LocalFrame* frame = m_document->frame();
   DCHECK(frame);
 
+  if (!willUnapply(source))
+    return;
+
   // Changes to the document may have been made since the last editing operation
   // that require a layout, as in <rdar://problem/5658603>. Low level
   // operations, like RemoveNodeCommand, don't require a layout because the high
@@ -126,11 +129,14 @@ void EditCommandComposition::unapply() {
   frame->editor().unappliedEditing(this);
 }
 
-void EditCommandComposition::reapply() {
+void EditCommandComposition::reapply(EditCommandSource source) {
   DCHECK(m_document);
   LocalFrame* frame = m_document->frame();
   DCHECK(frame);
 
+  if (!willReapply(source))
+    return;
+
   // Changes to the document may have been made since the last editing operation
   // that require a layout, as in <rdar://problem/5658603>. Low level
   // operations, like RemoveNodeCommand, don't require a layout because the high
@@ -146,6 +152,16 @@ void EditCommandComposition::reapply() {
   frame->editor().reappliedEditing(this);
 }
 
+bool EditCommandComposition::willUnapply(EditCommandSource) {
+  // TODO(chongz): Fire 'beforeinput' for 'historyUndo'.
+  return true;
+}
+
+bool EditCommandComposition::willReapply(EditCommandSource) {
+  // TODO(chongz): Fire 'beforeinput' for 'historyRedo'.
+  return true;
+}
+
 InputEvent::InputType EditCommandComposition::inputType() const {
   return m_inputType;
 }