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

ui/base/ime/input_method_auralinux.cc

 // Copyright 2013 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 "ui/base/ime/input_method_auralinux.h"
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/environment.h"
 #include "ui/base/ime/ime_bridge.h"
 #include "ui/base/ime/ime_engine_handler_interface.h"
 #include "ui/base/ime/linux/linux_input_method_context_factory.h"
 #include "ui/base/ime/text_input_client.h"
 #include "ui/events/event.h"
+#include "ui/gfx/geometry/rect.h"
 
 namespace {
 
 ui::IMEEngineHandlerInterface* GetEngine() {
   if (ui::IMEBridge::Get())
     return ui::IMEBridge::Get()->GetCurrentEngineHandler();
   return nullptr;
 }
 
 }  // namespace
@@ skipping 247 matching lines @@
     const TextInputClient* client) {
   UpdateContextFocusState();
   InputMethodBase::OnTextInputTypeChanged(client);
   // TODO(yoichio): Support inputmode HTML attribute.
 }
 
 void InputMethodAuraLinux::OnCaretBoundsChanged(const TextInputClient* client) {
   if (!IsTextInputClientFocused(client))
     return;
   NotifyTextInputCaretBoundsChanged(client);
-  context_->SetCursorLocation(GetTextInputClient()->GetCaretBounds());
+  context_->SetCursorLocation(
+      gfx::ScaleToEnclosingRect(client->GetCaretBounds(),
+                                client->GetScaleFactor()));

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

Can you update the doc [1] to mention that this is in physical-pixel space?
Alternatively, can this remain in DIP space, and the actual code where this is
used [2] does any necessary conversion to pixel-space?

[1]
https://cs.chromium.org/chromium/src/ui/base/ime/linux/linux_input_method_con...
[2]
https://cs.chromium.org/chromium/src/chrome/browser/ui/libgtkui/x11_input_met...

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

I've leveraged [2] and removed the GetScaleFactor method.

 
   if (!IsTextInputTypeNone() && text_input_type_ != TEXT_INPUT_TYPE_PASSWORD &&
       GetEngine())
     GetEngine()->SetCompositionBounds(GetCompositionBounds(client));
 }
 
 void InputMethodAuraLinux::CancelComposition(const TextInputClient* client) {
   if (!IsTextInputClientFocused(client))
     return;
 
@@ skipping 148 matching lines @@
     client->ConfirmCompositionText();
 
     if (GetEngine())
       GetEngine()->Reset();
   }
 
   ResetContext();
 }
 
 }  // namespace ui