Fix a bug in TextInputManager::GetCompositionRangeInfo

After the CL: https://codereview.chromium.org/2235283003 which implemented composition
range information tracking on the browser side for Mac, the method TIM::GetCompositionRangeInfo
was changed to take the RenderWidgetHostView for which the information is required. However,
the view pointer is not actually used and the method returns the stored information for |active_view_|
instead.

BUG=NONE

Review-Url: https://codereview.chromium.org/2814443003
Cr-Commit-Position: refs/heads/master@{#463391}

content/browser/renderer_host/text_input_manager.cc

@@ -72,11 +72,7 @@ const TextInputManager::SelectionRegion* TextInputManager::GetSelectionRegion(
 }
 
 const TextInputManager::CompositionRangeInfo*
-TextInputManager::GetCompositionRangeInfo(
-    RenderWidgetHostViewBase* view) const {
-  DCHECK(!view || IsRegistered(view));
-  if (!view)
-    view = active_view_;
+TextInputManager::GetCompositionRangeInfo() const {
   return active_view_ ? &composition_range_info_map_.at(active_view_) : nullptr;
 }
 

content/browser/renderer_host/text_input_manager.h

@@ -157,10 +157,8 @@ class CONTENT_EXPORT TextInputManager {
       RenderWidgetHostViewBase* view = nullptr) const;
 
   // Returns the composition range and character bounds information for the
-  // |view|. If |view| == nullptr, it will assume |active_view_| and return its
-  // state. If |active_view_| == nullptr, this method will return nullptr.
-  const TextInputManager::CompositionRangeInfo* GetCompositionRangeInfo(
-      RenderWidgetHostViewBase* view = nullptr) const;
+  // |active_view_|. Returns nullptr If |active_view_| == nullptr.
+  const TextInputManager::CompositionRangeInfo* GetCompositionRangeInfo() const;
 
   // The following method returns the text selection state for the given |view|.
   // If |view| == nullptr, it will assume |active_view_| and return its state.