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

content/browser/renderer_host/text_input_manager.h

Index: content/browser/renderer_host/text_input_manager.h
diff --git a/content/browser/renderer_host/text_input_manager.h b/content/browser/renderer_host/text_input_manager.h
index bef6e813cffacadb550a8593ac6df16f5bb69d11..68bb92bfd69e74e995377ffbd01f582584a1d01c 100644
--- a/content/browser/renderer_host/text_input_manager.h
+++ b/content/browser/renderer_host/text_input_manager.h
@@ -76,13 +76,13 @@ class CONTENT_EXPORT TextInputManager {
 
   // Returns the currently stored TextInputState. An state of nullptr can be
   // interpreted as a ui::TextInputType of ui::TEXT_INPUT_TYPE_NONE.
-  const TextInputState* GetTextInputState();
+  const TextInputState* GetTextInputState() const;
 
   // Returns the rect between selection bounds.
-  gfx::Rect GetSelectionBoundsRect();
+  gfx::Rect GetSelectionBoundsRect() const;
 
   // Returns a vector of rects representing the character bounds.
-  const std::vector<gfx::Rect>* GetCompositionCharacterBounds();
+  const std::vector<gfx::Rect>* GetCompositionCharacterBounds() const;
 
   // ---------------------------------------------------------------------------
   // The following methods are called by RWHVs on the tab to update their IME-