Move CreateURLLoaderFactory to the correct API group in WebViewPlugin.

The CreateURLLoaderFactory method is part of WebLocalFrameClient not
WebWidgetClient.

R=tommycli@chromium.org

Change-Id: I41b7c07f42151c58c01753f3da525073845638bd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1729205
Auto-Submit: danakj <danakj@chromium.org>
Reviewed-by: Tommy Li <tommycli@chromium.org>
Commit-Queue: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#683319}

components/plugins/renderer/webview_plugin.h

@@ -180,13 +180,13 @@ class WebViewPlugin : public blink::WebPlugin,
                        const gfx::Point&) override;
     void DidChangeCursor(const blink::WebCursorInfo& cursor) override;
     void ScheduleAnimation() override;
-    std::unique_ptr<blink::WebURLLoaderFactory> CreateURLLoaderFactory()
-        override;
 
     // WebLocalFrameClient methods:
     void BindToFrame(blink::WebNavigationControl* frame) override;
     void DidClearWindowObject() override;
     void FrameDetached(DetachType) override;
+    std::unique_ptr<blink::WebURLLoaderFactory> CreateURLLoaderFactory()
+        override;
 
    private:
     WebViewPlugin* plugin_;