Fix an IME bug where RWHImpl::ImeFinishCompositingText is called twice in a row

content/browser/renderer_host/render_widget_host_view_event_handler.cc

 // Copyright 2016 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/browser/renderer_host/render_widget_host_view_event_handler.h"
 
 #include "base/metrics/user_metrics.h"
 #include "base/metrics/user_metrics_action.h"
 #include "content/browser/renderer_host/input/touch_selection_controller_client_aura.h"
 #include "content/browser/renderer_host/overscroll_controller.h"
@@ skipping 608 matching lines @@
       return (event->flags() & kAllowedButtons) != 0;
     }
     default:
       break;
   }
 #endif
   return true;
 }
 
 void RenderWidgetHostViewEventHandler::FinishImeCompositionSession() {
-  if (!host_view_->GetTextInputClient()->HasCompositionText())
-    return;
-
-  TextInputManager* text_input_manager = host_view_->GetTextInputManager();
-  if (!!text_input_manager && !!text_input_manager->GetActiveWidget())
-    text_input_manager->GetActiveWidget()->ImeFinishComposingText(false);
+  // RenderWidgetHostViewAura keeps track of existing composition texts. The
+  // call to finish composition text should be made through the RWHVA itself
+  // otherwise the following call to cancel composition will lead to an extra
+  // IPC for finishing the ongoing composition (see https://crbug.com/723024).
+  host_view_->GetTextInputClient()->ConfirmCompositionText();
   host_view_->ImeCancelComposition();
 }
 
 void RenderWidgetHostViewEventHandler::ForwardMouseEventToParent(
     ui::MouseEvent* event) {
   // Needed to propagate mouse event to |window_->parent()->delegate()|, but
   // note that it might be something other than a WebContentsViewAura instance.
   // TODO(pkotwicz): Find a better way of doing this.
   // In fullscreen mode which is typically used by flash, don't forward
   // the mouse events to the parent. The renderer and the plugin process
@@ skipping 308 matching lines @@
     bool non_zero_delta =
         mouse_wheel_event.delta_x || mouse_wheel_event.delta_y;
     mouse_wheel_event.phase = non_zero_delta
                                   ? blink::WebMouseWheelEvent::kPhaseChanged
                                   : blink::WebMouseWheelEvent::kPhaseStationary;
     mouse_wheel_end_dispatch_timer_.Reset();
   }
 }
 
 }  // namespace content