Organize Layout/Paint-related hooks (blink-side).

Source/web/WebViewImpl.cpp

Index: Source/web/WebViewImpl.cpp
diff --git a/Source/web/WebViewImpl.cpp b/Source/web/WebViewImpl.cpp
index d6a3159e88ddd79c3f435e2acb3ab7c6e7ed4548..07880e02f1f49ed271d5d6c4d4df3a317bfd1cdb 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -1907,8 +1907,9 @@ void WebViewImpl::layout()
             m_shouldDispatchFirstVisuallyNonEmptyLayout = false;
             // TODO(esprehn): Move users of this callback to something
             // better, the heuristic for "visually non-empty" is bad.
-            // TODO(dglazkov): This should likely be a WebViewClient API.
+            // TODO(dglazkov): Remove this line after https://codereview.chromium.org/1319073003 lands.
             frame->loader().client()->dispatchDidFirstVisuallyNonEmptyLayout();
+            client()->didFirstVisuallyNonEmptyLayout();
         }
 
         if (m_shouldDispatchFirstLayoutAfterFinishedParsing && frame->document()->hasFinishedParsing())  {