Move WebInputMethodControllerImpl to core/exported/ & break dependencies.

third_party/WebKit/Source/web/WebViewImpl.h

Index: third_party/WebKit/Source/web/WebViewImpl.h
diff --git a/third_party/WebKit/Source/web/WebViewImpl.h b/third_party/WebKit/Source/web/WebViewImpl.h
index 116282d77adead0d14baf59e5ca6b5691e41c245..b3cfc49308b4af5fb049e12b7a0d01152c33b6c1 100644
--- a/third_party/WebKit/Source/web/WebViewImpl.h
+++ b/third_party/WebKit/Source/web/WebViewImpl.h
@@ -85,7 +85,7 @@ class UserGestureToken;
 class WebActiveGestureAnimation;
 class WebDevToolsAgentImpl;
 class WebElement;
-class WebInputMethodControllerImpl;
+class WebInputMethodController;
 class WebLayerTreeView;
 class WebLocalFrame;
 class WebLocalFrameBase;
@@ -504,7 +504,7 @@ class WEB_EXPORT WebViewImpl final
   // corresponding to the focused frame. It will return nullptr if there is no
   // focused frame, or if the there is one but it belongs to a different local
   // root.
-  WebInputMethodControllerImpl* GetActiveWebInputMethodController() const;
+  WebInputMethodController* GetActiveWebInputMethodController() const;
 
   void SetLastHiddenPagePopup(WebPagePopupImpl* page_popup) override {
     last_hidden_page_popup_ = page_popup;