Implement sampling profiler (chromium side change)

base/debug/trace_event.h

Index: base/debug/trace_event.h
diff --git a/base/debug/trace_event.h b/base/debug/trace_event.h
index 18feb33f3d0754897156a84c5027a7a64e9441dc..3ba430ae6b4fa7eb835f16e1635004b35d3472c1 100644
--- a/base/debug/trace_event.h
+++ b/base/debug/trace_event.h
@@ -957,7 +957,8 @@ TRACE_EVENT_API_CLASS_EXPORT extern \
 #define TRACE_EVENT_FLAG_COPY         (static_cast<unsigned char>(1 << 0))
 #define TRACE_EVENT_FLAG_HAS_ID       (static_cast<unsigned char>(1 << 1))
 #define TRACE_EVENT_FLAG_MANGLE_ID    (static_cast<unsigned char>(1 << 2))
-#define TRACE_EVENT_FLAG_SCOPE_OFFSET (static_cast<unsigned char>(1 << 3))
+#define TRACE_EVENT_FLAG_SAMPLING     (static_cast<unsigned char>(1 << 3))

[nduca, 2013/12/12 07:02:41]

we might have to update Blink's TraceEvent.h too?

+#define TRACE_EVENT_FLAG_SCOPE_OFFSET (static_cast<unsigned char>(1 << 4))
 
 #define TRACE_EVENT_FLAG_SCOPE_MASK   (static_cast<unsigned char>( \
     TRACE_EVENT_FLAG_SCOPE_OFFSET | (TRACE_EVENT_FLAG_SCOPE_OFFSET << 1)))
@@ -974,9 +975,9 @@ TRACE_EVENT_API_CLASS_EXPORT extern \
 
 // Enum reflecting the scope of an INSTANT event. Must fit within
 // TRACE_EVENT_FLAG_SCOPE_MASK.
-#define TRACE_EVENT_SCOPE_GLOBAL  (static_cast<unsigned char>(0 << 3))
-#define TRACE_EVENT_SCOPE_PROCESS (static_cast<unsigned char>(1 << 3))
-#define TRACE_EVENT_SCOPE_THREAD  (static_cast<unsigned char>(2 << 3))
+#define TRACE_EVENT_SCOPE_GLOBAL  (static_cast<unsigned char>(0 << 4))
+#define TRACE_EVENT_SCOPE_PROCESS (static_cast<unsigned char>(1 << 4))
+#define TRACE_EVENT_SCOPE_THREAD  (static_cast<unsigned char>(2 << 4))
 
 #define TRACE_EVENT_SCOPE_NAME_GLOBAL  ('g')
 #define TRACE_EVENT_SCOPE_NAME_PROCESS ('p')