Introduce ThreadedInputConnection behind a switch

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 ddd60cb9e6f1a7dace2cb3c442c7f8a78ed5de40..eebff7059efe60a43730f5062ef0f1a2e425804a 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -714,6 +714,8 @@ bool RenderWidget::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_HANDLER(ViewMsg_SetSurfaceIdNamespace, OnSetSurfaceIdNamespace)
 #if defined(OS_ANDROID)
     IPC_MESSAGE_HANDLER(InputMsg_ImeEventAck, OnImeEventAck)
+    IPC_MESSAGE_HANDLER(InputMsg_RequestTextInputStateUpdate,
+                        OnRequestTextInputStateUpdate)
     IPC_MESSAGE_HANDLER(ViewMsg_ShowImeIfNeeded, OnShowImeIfNeeded)
 #endif
     IPC_MESSAGE_HANDLER(ViewMsg_HandleCompositorProto, OnHandleCompositorProto)
@@ -1295,9 +1297,16 @@ void RenderWidget::UpdateTextInputState(ShowIme show_ime,
 
   bool new_can_compose_inline = CanComposeInline();
 
+  bool use_ime_thread = false;

[aelias_OOO_until_Jul13, 2016/01/23 03:21:39]

Let's make this default true on non-Android so that deleting ime-thread flag
becomes no-op change.

[Changwan Ryu, 2016/01/26 03:25:29]

Hmm... For other platforms if we set this as true they may send
UpdateTextInputState() even when the state hasn't changed. Is this ok?

[aelias_OOO_until_Jul13, 2016/01/26 05:21:18]

No, that shouldn't happen because change_source is always FROM_NON_IME now on
non-Android, right?

+#if defined(OS_ANDROID)
+  use_ime_thread = base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kUseImeThread);
+#endif
+
   // Only sends text input params if they are changed or if the ime should be
   // shown.
   if (show_ime == ShowIme::IF_NEEDED ||
+      (use_ime_thread && change_source == ChangeSource::FROM_IME) ||
       (text_input_type_ != new_type || text_input_mode_ != new_mode ||
        text_input_info_ != new_info ||
        can_compose_inline_ != new_can_compose_inline)
@@ -1795,12 +1804,19 @@ void RenderWidget::OnImeEventAck() {
   DCHECK_GE(text_input_info_history_.size(), 1u);
   text_input_info_history_.pop_front();
 }
+
+void RenderWidget::OnRequestTextInputStateUpdate() {
+  ImeEventGuard guard(this, false, true);

[aelias_OOO_until_Jul13, 2016/01/23 03:21:39]

This can't be nested so it seems unnecessarily indirect to use the guard. 
Please write:

  UpdateSelectionBounds();
  UpdateTextInputState(ShowIme::HIDE_IME, ChangeSource::FROM_IME);

[Changwan Ryu, 2016/01/26 03:25:29]

Done.

+}
 #endif
 
 bool RenderWidget::ShouldHandleImeEvent() {
 #if defined(OS_ANDROID)
   if (!webwidget_)
     return false;
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kUseImeThread))
+    return true;
 
   // We cannot handle IME events if there is any chance that the event we are
   // receiving here from the browser is based on the state that is different
@@ -1893,6 +1909,18 @@ void RenderWidget::set_next_paint_is_repaint_ack() {
   next_paint_flags_ |= ViewHostMsg_UpdateRect_Flags::IS_REPAINT_ACK;
 }
 
+bool RenderWidget::IsFromImeDefault() {
+#if defined(OS_ANDROID)
+  // When ChromiumInputConnection is used, we want to make sure that FROM_IME
+  // is set only for OnRequestTextInputStateUpdate() so that we can distinguish
+  // it from other updates so that we can wait for it safely.
+  return !base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kUseImeThread);
+#else
+  return true;

[aelias_OOO_until_Jul13, 2016/01/23 03:21:40]

Let's make this default false on non-Android.  It's no-op anyway (see #if
defined(USE_AURA) clause in UpdateTextInputState).

[Changwan Ryu, 2016/01/26 03:25:29]

Done.

+#endif
+}
+
 void RenderWidget::OnImeEventGuardStart(ImeEventGuard* guard) {
   if (!ime_event_guard_)
     ime_event_guard_ = guard;
@@ -2189,7 +2217,9 @@ void RenderWidget::setTouchAction(
 
 void RenderWidget::didUpdateTextOfFocusedElementByNonUserInput() {
 #if defined(OS_ANDROID)
-  text_field_is_dirty_ = true;
+  if (!base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kUseImeThread))
+    text_field_is_dirty_ = true;
 #endif
 }