[Editing] Introduce |CompositeEditCommand::willApplyEditing()| in prepare for 'beforeinput' (1/3)

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 e5bd64d18911c0fdada87faebfc8e658c3a56331..8e9f33a1e1d1e1348aee20a445f9137a3502cd4a 100644
--- a/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.cpp
+++ b/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.cpp
@@ -187,8 +187,7 @@ CompositeEditCommand::~CompositeEditCommand() {
   DCHECK(isTopLevelCommand() || !m_composition);
 }
 
-// TODO(chongz): Fire 'beforeinput' based on |EditCommandSource|.
-bool CompositeEditCommand::apply(EditCommandSource) {
+bool CompositeEditCommand::apply(EditCommandSource source) {
   DCHECK(!isCommandGroupWrapper());
   if (!endingSelection().isContentRichlyEditable()) {
     switch (inputType()) {
@@ -224,6 +223,9 @@ bool CompositeEditCommand::apply(EditCommandSource) {
   // the creation of VisiblePositions).
   document().updateStyleAndLayoutIgnorePendingStylesheets();
 
+  if (!willApplyEditing(source))
+    return false;
+
   LocalFrame* frame = document().frame();
   DCHECK(frame);
   EditingState editingState;
@@ -250,6 +252,11 @@ EditCommandComposition* CompositeEditCommand::ensureComposition() {
   return command->m_composition.get();
 }
 
+bool CompositeEditCommand::willApplyEditing(EditCommandSource) {
+  // TODO(chongz): Move all the 'beforeinput' dispatching logic here.
+  return true;
+}
+
 bool CompositeEditCommand::preservesTypingStyle() const {
   return false;
 }