Remove RenderViewObserver::Resized (try 2)

The only client was AutofillAgent; reimplement the functionality in a slightly different way. While we're at it, fix a bug where the browser-owned popup is hidden without the renderer's knowledge.

BUG=433486,449325

Review URL: https://codereview.chromium.org/854943002

Cr-Commit-Position: refs/heads/master@{#312346}
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 5b891f5..64c7bcd 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -1338,6 +1338,17 @@
     delegate_->WebContentsFocused(this);
 }
 
+void WebContentsImpl::RenderWidgetWasResized(
+    RenderWidgetHostImpl* render_widget_host) {
+  if (render_widget_host !=
+      static_cast<RenderFrameHostImpl*>(GetMainFrame())
+          ->GetRenderWidgetHost()) {
+    return;
+  }
+
+  FOR_EACH_OBSERVER(WebContentsObserver, observers_, MainFrameWasResized());
+}
+
 bool WebContentsImpl::PreHandleKeyboardEvent(
     const NativeWebKeyboardEvent& event,
     bool* is_keyboard_shortcut) {