Client Side Speed Index

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

Index: third_party/WebKit/Source/core/paint/PaintTiming.h
diff --git a/third_party/WebKit/Source/core/paint/PaintTiming.h b/third_party/WebKit/Source/core/paint/PaintTiming.h
index 3ac1d2db32233eb83b1e9b6f25b0bc92e4d069c6..80884370f0a7a77fc71d8568fb311cda364f22a8 100644
--- a/third_party/WebKit/Source/core/paint/PaintTiming.h
+++ b/third_party/WebKit/Source/core/paint/PaintTiming.h
@@ -7,7 +7,10 @@
 
 #include "core/dom/Document.h"
 #include "platform/Supplementable.h"
+#include "platform/geometry/IntRect.h"
 #include "platform/heap/Handle.h"
+#include "wtf/HashMap.h"
+#include "wtf/Int32Array.h"
 
 namespace blink {
 
@@ -23,12 +26,20 @@ public:
     void markFirstPaint();
     void markFirstTextPaint();
     void markFirstImagePaint();
+    void markPaintInvalidation(const IntRect* visualRect, int paintCount);
 
     // These return monotonically-increasing seconds.
     double firstPaint() const { return m_firstPaint; }
     double firstTextPaint() const { return m_firstTextPaint; }
     double firstImagePaint() const { return m_firstImagePaint; }
 
+    // When a consumer asks for the speed index, stop collecting and analyzing
+    // invalidation rects and give the result using information collected at the
+    // first request time.
+    double speedIndex(double referenceTime) const;
+
+    void setLoadCommitted() { m_loadCommitted = true; }
+
     DECLARE_VIRTUAL_TRACE();
 
 private:
@@ -39,6 +50,30 @@ private:
     double m_firstPaint = 0.0;
     double m_firstTextPaint = 0.0;
     double m_firstImagePaint = 0.0;
+    // Speed Index is calculated once when first queried, then cached.
+    mutable double m_speedIndex = 0.0;
+
+    // Members needed to calculate SpeedIndex:
+
+    // Ignore all paint invalidations until the load commits.
+    bool m_loadCommitted = false;
+
+    IntRect m_viewPortRect;
+    int m_lastPaintCount = 0;
+
+    // Forbids duplicate rect invalidations that occur before painting.
+    WTF::HashSet<unsigned> frameRects;
+
+    // Counts rect occurrences.
+    typedef WTF::HashMap<unsigned, int> RectCountMap;
+    RectCountMap m_rectCounts;
+
+    double m_lastPaintInvalidationTime = 0.0;
+
+    // The current area under the curve of "painted area over time."
+    double m_totalLoadedArea = 0.0;
+    // The total amount of painted area.
+    double m_totalContributions = 0.0;
 
     RawPtrWillBeMember<Document> m_document;
 };