Introduce WebInputMethodController to blink

third_party/WebKit/public/web/WebFrameWidget.h

Index: third_party/WebKit/public/web/WebFrameWidget.h
diff --git a/third_party/WebKit/public/web/WebFrameWidget.h b/third_party/WebKit/public/web/WebFrameWidget.h
index 43c6ddf9d72317144d377d37d6c8fcd2dab41c06..340e19e0e05f2400053c84f446fbab8e0f3856da 100644
--- a/third_party/WebKit/public/web/WebFrameWidget.h
+++ b/third_party/WebKit/public/web/WebFrameWidget.h
@@ -38,6 +38,7 @@
 namespace blink {
 
 class WebLocalFrame;
+class WebInputMethodController;
 class WebView;
 class WebWidgetClient;
 
@@ -75,6 +76,12 @@ public:
 
     // WebWidget implementation.
     bool isWebFrameWidget() const final { return true; }
+
+    // Current instance of the active WebInputMethodController, that is, the
+    // WebInputMethodController corresponding to (and owned by) the focused
+    // WebLocalFrameImpl. It might return nullptr when there are no focused
+    // frames or possibly when the WebFrameWidget does not accept IME events.
+    virtual WebInputMethodController* getActiveWebInputMethodController() const = 0;
 };
 
 } // namespace blink