Require ACK for editor-related changes not originating from browser.

content/renderer/render_widget.cc

Index: content/renderer/render_widget.cc
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index f0a1e6da64b87c9b04acf348003a2d0831b022d9..4e2338a502ea9344eaef944711cb0201b4aebb6a 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -180,6 +180,10 @@ RenderWidget::RenderWidget(WebKit::WebPopupType popup_type,
       screen_info_(screen_info),
       device_scale_factor_(screen_info_.deviceScaleFactor),
       is_threaded_compositing_enabled_(false),
+#if defined(OS_ANDROID)
+      has_ordered_ime_processing_(false),
+      outstanding_ime_acks_(0),
+#endif
       weak_ptr_factory_(this) {
   if (!swapped_out)
     RenderProcess::current()->AddRefProcess();
@@ -189,6 +193,11 @@ RenderWidget::RenderWidget(WebKit::WebPopupType popup_type,
   is_threaded_compositing_enabled_ =
       CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableThreadedCompositing);
+#if defined(OS_ANDROID)
+  has_ordered_ime_processing_ =
+      CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableOrderedImeProcessing);
+#endif
 
   RenderProcessVisibilityManager::GetInstance()->WidgetVisibilityChanged(true);
 }
@@ -339,6 +348,7 @@ bool RenderWidget::OnMessageReceived(const IPC::Message& message) {
 #if defined(OS_ANDROID)
     IPC_MESSAGE_HANDLER(ViewMsg_ImeBatchStateChanged, OnImeBatchStateChanged)
     IPC_MESSAGE_HANDLER(ViewMsg_ShowImeIfNeeded, OnShowImeIfNeeded)
+    IPC_MESSAGE_HANDLER(ViewMsg_ImeEventAck, OnImeEventAck)
 #endif
     IPC_MESSAGE_HANDLER(ViewMsg_Snapshot, OnSnapshot)
     IPC_MESSAGE_HANDLER(ViewMsg_SetBrowserRenderingStats,
@@ -1525,7 +1535,8 @@ void RenderWidget::willBeginCompositorFrame() {
   // is done.
   UpdateTextInputType();
 #if defined(OS_ANDROID)
-  UpdateTextInputState(DO_NOT_SHOW_IME);
+  if (!has_ordered_ime_processing())
+    UpdateTextInputState(DO_NOT_SHOW_IME);
 #endif
   UpdateSelectionBounds();
 
@@ -1769,7 +1780,7 @@ void RenderWidget::OnImeSetComposition(
     const string16& text,
     const std::vector<WebCompositionUnderline>& underlines,
     int selection_start, int selection_end) {
-  if (!webwidget_)
+  if (!ShouldHandleImeEvent())
     return;
   ImeEventGuard guard(this);
   if (!webwidget_->setComposition(
@@ -1785,7 +1796,7 @@ void RenderWidget::OnImeSetComposition(
 
 void RenderWidget::OnImeConfirmComposition(
     const string16& text, const ui::Range& replacement_range) {
-  if (!webwidget_)
+  if (!ShouldHandleImeEvent())
     return;
   ImeEventGuard guard(this);
   handling_input_event_ = true;
@@ -1963,8 +1974,32 @@ void RenderWidget::OnImeBatchStateChanged(bool is_begin) {
 void RenderWidget::OnShowImeIfNeeded() {
   UpdateTextInputState(SHOW_IME_IF_NEEDED);
 }
+
+void RenderWidget::IncrementOutstandingImeEventAcks() {
+  if (has_ordered_ime_processing())
+    ++outstanding_ime_acks_;
+}
+
+void RenderWidget::OnImeEventAck() {
+  if (has_ordered_ime_processing()) {
+    --outstanding_ime_acks_;
+    DCHECK(outstanding_ime_acks_ >= 0);
+  }
+}
+
+bool RenderWidget::HasOutstandingImeEventAcks() {
+  return has_ordered_ime_processing() && outstanding_ime_acks_ > 0;
+}
 #endif
 
+bool RenderWidget::ShouldHandleImeEvent() {
+#if defined(OS_ANDROID)
+  return !!webwidget_ && !HasOutstandingImeEventAcks();
+#else
+  return !!webwidget_;
+#endif
+}
+
 void RenderWidget::SetDeviceScaleFactor(float device_scale_factor) {
   if (device_scale_factor_ == device_scale_factor)
     return;
@@ -2077,7 +2112,8 @@ void RenderWidget::FinishHandlingImeEvent() {
   // ime event.
   UpdateSelectionBounds();
 #if defined(OS_ANDROID)
-  UpdateTextInputState(DO_NOT_SHOW_IME);
+  if (!has_ordered_ime_processing())
+    UpdateTextInputState(DO_NOT_SHOW_IME);
 #endif
 }
 
@@ -2132,6 +2168,7 @@ void RenderWidget::UpdateTextInputState(ShowIme show_ime) {
     p.composition_end = new_info.compositionEnd;
     p.can_compose_inline = new_can_compose_inline;
     p.show_ime_if_needed = show_ime_if_needed;
+    IncrementOutstandingImeEventAcks();
     Send(new ViewHostMsg_TextInputStateChanged(routing_id(), p));
 
     text_input_info_ = new_info;