DO NOT SUBMIT: Handle nested message correctly for OnRequestTextInputState()

content/renderer/render_widget.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/render_widget.h"
 
 #include <utility>
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
@@ skipping 1644 matching lines @@
 void RenderWidget::OnImeEventSentForAck(const blink::WebTextInputInfo& info) {
   text_input_info_history_.push_back(info);
 }
 
 void RenderWidget::OnImeEventAck() {
   DCHECK_GE(text_input_info_history_.size(), 1u);
   text_input_info_history_.pop_front();
 }
 
 void RenderWidget::OnRequestTextInputStateUpdate() {
-  DCHECK(!ime_event_guard_);

[Changwan Ryu, 2016/04/07 11:48:18]

FYI, this DCHECK was introduced in 
https://codereview.chromium.org/1278593004/diff2/260001:360001/content/render...

-  UpdateSelectionBounds();
-  UpdateTextInputState(ShowIme::HIDE_IME, ChangeSource::FROM_IME);
+  ImeEventGuard guard(this);
+  ime_event_guard_->set_from_ime(true);
 }
 #endif
 
 bool RenderWidget::ShouldHandleImeEvent() {
 #if defined(OS_ANDROID)
   if (!webwidget_)
     return false;
   if (IsUsingImeThread())
     return true;
 
@@ skipping 100 matching lines @@
 }
 
 void RenderWidget::OnImeEventGuardStart(ImeEventGuard* guard) {
   if (!ime_event_guard_)
     ime_event_guard_ = guard;
 }
 
 void RenderWidget::OnImeEventGuardFinish(ImeEventGuard* guard) {
   if (ime_event_guard_ != guard) {
 #if defined(OS_ANDROID)
-    // In case a from-IME event (e.g. touch) ends up in not-from-IME event
-    // (e.g. long press gesture), we want to treat it as not-from-IME event
-    // so that ReplicaInputConnection can make changes to its Editable model.
-    // Therefore, we want to mark this text state update as 'from IME' only
-    // when all the nested events are all originating from IME.
-    ime_event_guard_->set_from_ime(
-        ime_event_guard_->from_ime() && guard->from_ime());
+    if (IsUsingImeThread()) {
+      // When a from-IME event (OnRequestTextInputStateUpdate) as nested by a
+      // not-from-IME event (e.g. HandleInputEvent), then we still need to
+      // deliver the data. Otherwise, ThreadedInputConnection might hang.
+      ime_event_guard_->set_from_ime(
+          ime_event_guard_->from_ime() || guard->from_ime());
+    } else {
+      // In case a from-IME event (e.g. touch) ends up in not-from-IME event
+      // (e.g. long press gesture), we want to treat it as not-from-IME event
+      // so that ReplicaInputConnection can make changes to its Editable model.
+      // Therefore, we want to mark this text state update as 'from IME' only
+      // when all the nested events are all originating from IME.
+      ime_event_guard_->set_from_ime(
+          ime_event_guard_->from_ime() && guard->from_ime());
+    }
 #endif
     return;
   }
   ime_event_guard_ = nullptr;
 
   // While handling an ime event, text input state and selection bounds updates
   // are ignored. These must explicitly be updated once finished handling the
   // ime event.
   UpdateSelectionBounds();
 #if defined(OS_ANDROID)
@@ skipping 343 matching lines @@
 }
 
 float RenderWidget::GetOriginalDeviceScaleFactor() const {
   return
       screen_metrics_emulator_ ?
       screen_metrics_emulator_->original_screen_info().deviceScaleFactor :
       device_scale_factor_;
 }
 
 }  // namespace content