[refactor] content::TextInputManager - Make some methods const and initialize/cleanup IME maps

content/browser/renderer_host/text_input_manager.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/text_input_manager.h"
 
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/browser/renderer_host/render_widget_host_view_base.h"
 #include "content/common/view_messages.h"
 #include "ui/gfx/geometry/rect.h"
@@ skipping 34 matching lines @@
   for (auto view : views)
     Unregister(view);
 }
 
 RenderWidgetHostImpl* TextInputManager::GetActiveWidget() const {
   return !!active_view_ ? static_cast<RenderWidgetHostImpl*>(
                               active_view_->GetRenderWidgetHost())
                         : nullptr;
 }
 
-const TextInputState* TextInputManager::GetTextInputState() {
-  return !!active_view_ ? &text_input_state_map_[active_view_] : nullptr;
+const TextInputState* TextInputManager::GetTextInputState() const{
+  return !!active_view_ ? &text_input_state_map_.at(active_view_) : nullptr;
 }
 
-gfx::Rect TextInputManager::GetSelectionBoundsRect() {
+gfx::Rect TextInputManager::GetSelectionBoundsRect() const {
   if (!active_view_)
     return gfx::Rect();
 
   return gfx::RectBetweenSelectionBounds(
-      selection_region_map_[active_view_].anchor,
-      selection_region_map_[active_view_].focus);
+      selection_region_map_.at(active_view_).anchor,
+      selection_region_map_.at(active_view_).focus);
 }
 
 const std::vector<gfx::Rect>*
-TextInputManager::GetCompositionCharacterBounds() {
+TextInputManager::GetCompositionCharacterBounds() const {
   return !!active_view_
-             ? &composition_range_info_map_[active_view_].character_bounds
+             ? &composition_range_info_map_.at(active_view_).character_bounds
              : nullptr;
 }
 
 void TextInputManager::UpdateTextInputState(
     RenderWidgetHostViewBase* view,
     const TextInputState& text_input_state) {
   DCHECK(IsRegistered(view));
 
   // Since |view| is registgered, we already have a previous value for its
   // TextInputState.
@@ skipping 89 matching lines @@
   }
 
   FOR_EACH_OBSERVER(Observer, observer_list_,
                     OnImeCompositionRangeChanged(this, view));
 }
 
 void TextInputManager::Register(RenderWidgetHostViewBase* view) {
   DCHECK(!IsRegistered(view));
 
   text_input_state_map_[view] = TextInputState();
+  selection_region_map_[view] = SelectionRegion();
+  composition_range_info_map_[view] = CompositionRangeInfo();

[Charlie Reis, 2016/07/20 23:08:20]

Yikes.  I would suggest adding a comment to the .h file where this block of
members is declared, mentioning (reminding) they're initialized in Register and
cleared in Unregister (per view).

[EhsanK, 2016/07/21 16:06:02]

Done.

 }
 
 void TextInputManager::Unregister(RenderWidgetHostViewBase* view) {
   DCHECK(IsRegistered(view));
 
   text_input_state_map_.erase(view);
+  selection_region_map_.erase(view);
+  composition_range_info_map_.erase(view);
+
   if (active_view_ == view) {
     active_view_ = nullptr;
     NotifyObserversAboutInputStateUpdate(view, true);
   }
   view->DidUnregisterFromTextInputManager(this);
 }
 
 bool TextInputManager::IsRegistered(RenderWidgetHostViewBase* view) const {
   return text_input_state_map_.count(view) == 1;
 }
@@ skipping 29 matching lines @@
 TextInputManager::SelectionRegion::SelectionRegion(
     const SelectionRegion& other) = default;
 
 TextInputManager::CompositionRangeInfo::CompositionRangeInfo() {}
 
 TextInputManager::CompositionRangeInfo::CompositionRangeInfo(
     const CompositionRangeInfo& other) = default;
 
 TextInputManager::CompositionRangeInfo::~CompositionRangeInfo() {}
 
-}  // namespace content
+}  // namespace content