scheduler: Detect load RAIL mode

third_party/WebKit/Source/core/paint/PaintTiming.cpp

Index: third_party/WebKit/Source/core/paint/PaintTiming.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintTiming.cpp b/third_party/WebKit/Source/core/paint/PaintTiming.cpp
index f87085b838c3eeaf5de00e7bed4e77de66bd05c9..d982e0c38b482887f75eab390d14695e21a4d6ec 100644
--- a/third_party/WebKit/Source/core/paint/PaintTiming.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintTiming.cpp
@@ -5,8 +5,11 @@
 #include "core/paint/PaintTiming.h"
 
 #include "core/dom/Document.h"
+#include "core/frame/FrameView.h"
+#include "core/frame/LocalFrame.h"
 #include "core/loader/DocumentLoader.h"
 #include "platform/tracing/TraceEvent.h"
+#include "public/platform/WebFrameScheduler.h"
 
 namespace blink {
 
@@ -65,6 +68,25 @@ void PaintTiming::markFirstImagePaint() {
   notifyPaintTimingChanged();
 }
 
+void PaintTiming::markFirstMeaningfulPaintCandidate() {
+  // The first meaningful paint candidate can be reported very early, even
+  // before the first contentful paint. To cut down on false positives, we only
+  // report the first meaningful paint candidate after the first contentful
+  // paint.
+  if (!m_firstContentfulPaint)
+    return;
+  // Ignore the first meaningful paint candidate as this generally is the first
+  // contentful paint itself.
+  if (!m_seenFirstMeaningfulPaintCandidate) {
+    m_seenFirstMeaningfulPaintCandidate = true;
+    return;
+  }
+  if (m_document->frame() && m_document->frame()->view() &&
+      !m_document->frame()->view()->parent()) {
+    m_document->frame()->frameScheduler()->onFirstMeaningfulPaint();
+  }
+}
+
 void PaintTiming::setFirstMeaningfulPaint(double stamp) {
   DCHECK_EQ(m_firstMeaningfulPaint, 0.0);
   m_firstMeaningfulPaint = stamp;