updating Input field value by script should reset IME composition.

third_party/WebKit/public/web/WebViewClient.h

Index: third_party/WebKit/public/web/WebViewClient.h
diff --git a/third_party/WebKit/public/web/WebViewClient.h b/third_party/WebKit/public/web/WebViewClient.h
index cc0da0843bb1f4e217db41b9010ba620fbb04167..6c5ff60d4777eec2639aed077139773d0388f1af 100644
--- a/third_party/WebKit/public/web/WebViewClient.h
+++ b/third_party/WebKit/public/web/WebViewClient.h
@@ -167,6 +167,7 @@ class WebViewClient : protected WebWidgetClient {
   // node, |toNode| is the newly focused node. Either can be null.
   virtual void FocusedNodeChanged(const WebNode& from_node,
                                   const WebNode& to_node) {}
+  virtual void DidCancelCompositionOnSelectionChange() {}
 
   // Called to check if layout update should be processed.
   virtual bool CanUpdateLayout() { return false; }