Move didFocus from WebWidgetClient to WebViewClient.

content/renderer/render_widget.cc

Index: content/renderer/render_widget.cc
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index 7797b31cf3041a4f58b09656ab2a484985418220..734ebeef76554ebbd13e858fd62b3f36b46623a9 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -1219,9 +1219,6 @@ void RenderWidget::show(WebNavigationPolicy) {
   SetPendingWindowRect(initial_rect_);
 }
 
-void RenderWidget::didFocus() {
-}
-
 void RenderWidget::DoDeferredClose() {
   WillCloseLayerTreeView();
   Send(new ViewHostMsg_Close(routing_id_));