Move onMouseDown from WebWidgetClient to WebViewClient.

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 996b7730254c8e210de0247b914af84f4f6cb0b6..9e55f42979962d2145253e07f10ce1840f695b6b 100644
--- a/third_party/WebKit/public/web/WebViewClient.h
+++ b/third_party/WebKit/public/web/WebViewClient.h
@@ -196,6 +196,14 @@ public:
     // Called when the View acquires focus.
     virtual void didFocus() {}
 
+    // TODO(lfg): The callback below is exposed in RenderViewObserver and only
+    // used to implement autofill. We should figure out a better way to plumb
+    // this.
+    // Called immediately after a mousedown event is dispatched due to a mouse
+    // press or gesture tap.
+    // Note: This is called even when the mouse down event is prevent default.
+    virtual void onMouseDown(const WebNode& mouseDownNode) { }
+
     // Session history -----------------------------------------------------
 
     // Tells the embedder to navigate back or forward in session history by
@@ -266,7 +274,6 @@ public:
     void didUpdateTextOfFocusedElementByNonUserInput() override {}
     void hasTouchEventHandlers(bool) override {}
     void initializeLayerTreeView() override {}
-    void onMouseDown(const WebNode& mouseDownNode) override {}
     void resetInputMethod() override {}
     WebScreenInfo screenInfo() override { return WebScreenInfo(); }
     void setToolTipText(const WebString&, WebTextDirection hint) override {}