Revert restartInput change off the M57 release branch.

content/renderer/input/render_widget_input_handler_delegate.h

Index: content/renderer/input/render_widget_input_handler_delegate.h
diff --git a/content/renderer/input/render_widget_input_handler_delegate.h b/content/renderer/input/render_widget_input_handler_delegate.h
index 714bd5feec60459b0729c115e47e9022f2d91eec..ad3518874f349b2a8d9291092ac489ec2b0e7351 100644
--- a/content/renderer/input/render_widget_input_handler_delegate.h
+++ b/content/renderer/input/render_widget_input_handler_delegate.h
@@ -72,9 +72,6 @@ class CONTENT_EXPORT RenderWidgetInputHandlerDelegate {
   // Send an update of text input state to the browser process.
   virtual void UpdateTextInputState() = 0;
 
-  // Clear the text input state.
-  virtual void ClearTextInputState() {}
-
   // Notifies that a gesture event is about to be handled.
   // Returns true if no further handling is needed. In that case, the event
   // won't be sent to WebKit.