Use the physical-pixel space for native IME on linux platform.

content/browser/renderer_host/render_widget_host_view_aura.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/browser/renderer_host/render_widget_host_view_aura.h"
 
 #include <set>
 #include <utility>
 
 #include "base/auto_reset.h"
@@ skipping 1270 matching lines @@
     screen_position_client->ConvertPointFromScreen(window_, &end);
     return gfx::Rect(origin.x(),
                      origin.y(),
                      end.x() - origin.x(),
                      end.y() - origin.y());
   }
 
   return rect;
 }
 
+float RenderWidgetHostViewAura::GetScaleFactor() const {
+  return display::Screen::GetScreen()
+      ->GetDisplayNearestWindow(window_).device_scale_factor();

[sadrul, 2016/12/22 01:30:22]

just return |device_scale_factor_|?

[Shu Chen, 2016/12/22 03:02:27]

Ah, I didn't notice that. Thanks for pointing it out.

I've removed the GetScaleFactor method.

+}
+
 gfx::Rect RenderWidgetHostViewAura::GetCaretBounds() const {
   if (!text_input_manager_ || !text_input_manager_->GetActiveWidget())
     return gfx::Rect();
 
   const TextInputManager::SelectionRegion* region =
       text_input_manager_->GetSelectionRegion();
   return ConvertRectToScreen(
       gfx::RectBetweenSelectionBounds(region->anchor, region->focus));
 }
 
@@ skipping 1079 matching lines @@
 
 void RenderWidgetHostViewAura::SetPopupChild(
     RenderWidgetHostViewAura* popup_child_host_view) {
   popup_child_host_view_ = popup_child_host_view;
   event_handler_->SetPopupChild(
       popup_child_host_view,
       popup_child_host_view ? popup_child_host_view->event_handler() : nullptr);
 }
 
 }  // namespace content