LongTaskTiming: add idl, Experiment flag, PerformanceEntry and basic implementation

third_party/WebKit/Source/core/timing/PerformanceBaseTest.cpp

Index: third_party/WebKit/Source/core/timing/PerformanceBaseTest.cpp
diff --git a/third_party/WebKit/Source/core/timing/PerformanceBaseTest.cpp b/third_party/WebKit/Source/core/timing/PerformanceBaseTest.cpp
index 8b7c6f0b13804d40e1b98648d4a6fb13bda15221..4bbe857941d3358df74ed7fb771842e1b9e5334c 100644
--- a/third_party/WebKit/Source/core/timing/PerformanceBaseTest.cpp
+++ b/third_party/WebKit/Source/core/timing/PerformanceBaseTest.cpp
@@ -5,8 +5,10 @@
 #include "core/timing/Performance.h"
 
 #include "core/timing/PerformanceBase.h"
+#include "core/timing/PerformanceLongTaskTiming.h"
 #include "core/timing/PerformanceObserver.h"
 #include "core/timing/PerformanceObserverCallback.h"
+#include "core/timing/PerformanceObserverInit.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace blink {
@@ -22,6 +24,11 @@ public:
 
     int numObservers() { return m_observers.size(); }
 
+    int numLongTaskTimingEntries()
+    {
+        return m_longTaskTimingBuffer.size();
+    }
+
     DEFINE_INLINE_TRACE()
     {
         PerformanceBase::trace(visitor);
@@ -88,4 +95,23 @@ TEST_F(PerformanceBaseTest, Activate)
     EXPECT_EQ(0, m_base->numActiveObservers());
 }
 
+TEST_F(PerformanceBaseTest, AddLongTaskTiming)
+{
+    // Add a long task entry, but no observer registered.
+    m_base->addLongTaskTiming(1234, 5678, "www.foo.com/bar");
+    EXPECT_EQ(0, m_base->numLongTaskTimingEntries()); // has no effect
+
+    // Make an observer for longtask
+    NonThrowableExceptionState exceptionState;
+    PerformanceObserverInit options;
+    Vector<String> entryTypeVec;
+    entryTypeVec.append("longtask");
+    options.setEntryTypes(entryTypeVec);
+    m_observer->observe(options, exceptionState);
+
+    // Add a long task entry
+    m_base->addLongTaskTiming(1234, 5678, "www.foo.com/bar");
+    EXPECT_EQ(1, m_base->numLongTaskTimingEntries()); // added an entry
+}
+
 } // namespace blink