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 4f95ddfb6d8fea37c74c90f1e9df0369f3e741f3..1f5f159ab8b11121c048114cb3a73fa5c0fbd41b 100644
--- a/Source/core/frame/Frame.cpp
+++ b/Source/core/frame/Frame.cpp
@@ -53,6 +53,18 @@ 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);

[chrishtr, 2015/03/27 01:13:02]

currentTime() is already in seconds, no?

[MikeB, 2015/04/14 18:05:45]

Yes, it's making "next" start off at a very large number, seeded by the time. It
will increment by "1" though, for each frame. If it used "seconds" then there's
a very real chance of collisions. 

+    return ++next;
+}
+
+} // namespace
+
 DEFINE_DEBUG_ONLY_GLOBAL(WTF::RefCountedLeakCounter, frameCounter, ("Frame"));
 
 Frame::~Frame()
@@ -286,6 +298,7 @@ Frame::Frame(FrameClient* client, FrameHost* host, FrameOwner* owner)
     , m_host(host)
     , m_owner(owner)
     , m_client(client)
+    , m_frameID(generateFrameID())
     , m_isLoading(false)
 {
     ASSERT(page());