Make rendering timeouts work even if paint data received early

third_party/WebKit/Source/web/WebViewImpl.cpp

Index: third_party/WebKit/Source/web/WebViewImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebViewImpl.cpp b/third_party/WebKit/Source/web/WebViewImpl.cpp
index 6f670d37d17c972cad3066e025735e459336c8ef..719e53e481e548c21f6b3d7fb0eddd3e2efec49d 100644
--- a/third_party/WebKit/Source/web/WebViewImpl.cpp
+++ b/third_party/WebKit/Source/web/WebViewImpl.cpp
@@ -449,6 +449,7 @@ WebViewImpl::WebViewImpl(WebViewClient* client)
     , m_userGestureObserved(false)
     , m_shouldDispatchFirstVisuallyNonEmptyLayout(false)
     , m_shouldDispatchFirstLayoutAfterFinishedParsing(false)
+    , m_shouldDispatchFirstPaintAfterLoad(false)
     , m_displayMode(WebDisplayModeBrowser)
     , m_elasticOverscroll(FloatSize())
 {
@@ -3867,6 +3868,11 @@ void WebViewImpl::didCommitLoad(bool isNewNavigation, bool isNavigationWithinPag
         m_pageImportanceSignals.onCommitLoad();
     }
 
+    if (m_shouldDispatchFirstPaintAfterLoad) {
+        m_shouldDispatchFirstPaintAfterLoad = false;
+        client()->didFirstPaintAfterLoad();
+    }
+
     // Give the visual viewport's scroll layer its initial size.
     page()->frameHost().visualViewport().mainFrameDidChangeSize();
 
@@ -4147,6 +4153,7 @@ void WebViewImpl::setRootGraphicsLayer(GraphicsLayer* layer)
         m_layerTreeView->clearRootLayer();
         m_shouldDispatchFirstVisuallyNonEmptyLayout = true;
         m_shouldDispatchFirstLayoutAfterFinishedParsing = true;
+        m_shouldDispatchFirstPaintAfterLoad = true;
         page()->frameHost().visualViewport().clearLayersForTreeView(m_layerTreeView);
     }
 }