Blink changes to record interest rects for http://w3c.github.io/frame-timing/

Source/core/frame/Frame.cpp

Index: Source/core/frame/Frame.cpp
diff --git a/Source/core/frame/Frame.cpp b/Source/core/frame/Frame.cpp
index 05ce11401e7fe5d00669b50c267b724c022ee314..ba073ef947b4075e74068dd6c04a3f891be7deb3 100644
--- a/Source/core/frame/Frame.cpp
+++ b/Source/core/frame/Frame.cpp
@@ -55,6 +55,18 @@ namespace blink {
 
 using namespace HTMLNames;
 
+namespace {
+
+int64_t generateFrameID()
+{
+    // Initialize to the current time to reduce the likelihood of generating
+    // identifiers that overlap with those from past/future browser sessions.
+    static int64_t next = static_cast<int64_t>(currentTime() * 1000000.0);
+    return ++next;
+}
+
+} // namespace
+
 DEFINE_DEBUG_ONLY_GLOBAL(WTF::RefCountedLeakCounter, frameCounter, ("Frame"));
 
 Frame::~Frame()
@@ -290,6 +302,7 @@ Frame::Frame(FrameClient* client, FrameHost* host, FrameOwner* owner)
     , m_host(host)
     , m_owner(owner)
     , m_client(client)
+    , m_frameID(generateFrameID())
     , m_remotePlatformLayer(nullptr)
     , m_isLoading(false)
 {