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

components/arc/ime/arc_ime_service.h

 // 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.
 
 #ifndef COMPONENTS_ARC_IME_ARC_IME_SERVICE_H_
 #define COMPONENTS_ARC_IME_ARC_IME_SERVICE_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 68 matching lines @@
   void OnKeyboardBoundsChanging(const gfx::Rect& rect) override;
   void OnKeyboardClosed() override;
 
   // Overridden from ui::TextInputClient:
   void SetCompositionText(const ui::CompositionText& composition) override;
   void ConfirmCompositionText() override;
   void ClearCompositionText() override;
   void InsertText(const base::string16& text) override;
   void InsertChar(const ui::KeyEvent& event) override;
   ui::TextInputType GetTextInputType() const override;
+  float GetScaleFactor() const override;
   gfx::Rect GetCaretBounds() const override;
 
   // Overridden from ui::TextInputClient (with default implementation):
   // TODO(kinaba): Support each of these methods to the extent possible in
   // Android input method API.
   ui::TextInputMode GetTextInputMode() const override;
   base::i18n::TextDirection GetTextDirection() const override;
   int GetTextInputFlags() const override;
   bool CanComposeInline() const override;
   bool GetCompositionCharacterBounds(uint32_t index,
@@ skipping 30 matching lines @@
 
   ui::InputMethod* test_input_method_;
   bool is_focus_observer_installed_;
 
   DISALLOW_COPY_AND_ASSIGN(ArcImeService);
 };
 
 }  // namespace arc
 
 #endif  // COMPONENTS_ARC_IME_ARC_IME_SERVICE_H_