Use NESTABLE_ASYNC APIs to get NetLog data into Tracing

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 f9dc1c94d6d65b885772a4b1bf3b16005c58c2e9..f0e96a3ddbe61fa40cb0a73cb1bc53c84614e0b4 100644
--- a/base/debug/trace_event.h
+++ b/base/debug/trace_event.h
@@ -634,6 +634,39 @@
         static_cast<int>(base::PlatformThread::CurrentId()), \
         timestamp, TRACE_EVENT_FLAG_NONE)
 
+
+// Records a single NET_LOG_BEGIN event called "name" immediately, with 2
+// associated arguments. If the category is not enabled, then this
+// does nothing.
+// - category and name strings must have application lifetime (statics or
+//   literals). They may not include " chars.
+// - |id| is used to match the NET_LOG_BEGIN event with the NET_LOG_END event.
+//   Events are considered to match if their category_group, name and id values
+//   all match. |id| must either be a pointer or an integer value up to 64 bits.
+//   If it's a pointer, the bits will be xored with a hash of the process ID so
+//   that the same pointer on two different processes will not collide.
+// NET_LOG_ events are supposed to be used for logging NetLog events only.
+
+#define TRACE_EVENT_NET_LOG_BEGIN(category_group, name, id, arg1_name, \

[dsinclair, 2014/09/02 20:11:45]

Each of these macros should have a 2 on the end for consistency with other trace
macros.

[xunjieli, 2014/09/02 20:26:06]

Done.

+        arg1_val, arg2_name, arg2_val) \
+    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_NET_LOG_BEGIN, \
+        category_group, name, id, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val, \
+        arg2_name, arg2_val)
+// Records a single NET_LOG_END event for "name" immediately. If the category
+// is not enabled, then this does nothing.
+#define TRACE_EVENT_NET_LOG_END(category_group, name, id, arg1_name, arg1_val, \
+        arg2_name, arg2_val) \
+    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_NET_LOG_END, \
+        category_group, name, id, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val, \
+        arg2_name, arg2_val)
+// Records a single NET_LOG_INSTANT event for "name" immediately.
+// If the category is not enabled, then this does nothing.
+#define TRACE_EVENT_NET_LOG_INSTANT(category_group, name, id, arg1_name, \
+        arg1_val, arg2_name, arg2_val) \
+    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_NET_LOG_INSTANT, \
+        category_group, name, id, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val, \
+        arg2_name, arg2_val)
+
 // Records a single FLOW_BEGIN event called "name" immediately, with 0, 1 or 2
 // associated arguments. If the category is not enabled, then this
 // does nothing.
@@ -972,6 +1005,9 @@ TRACE_EVENT_API_CLASS_EXPORT extern \
 #define TRACE_EVENT_PHASE_CREATE_OBJECT ('N')
 #define TRACE_EVENT_PHASE_SNAPSHOT_OBJECT ('O')
 #define TRACE_EVENT_PHASE_DELETE_OBJECT ('D')
+#define TRACE_EVENT_PHASE_NET_LOG_BEGIN ('b')
+#define TRACE_EVENT_PHASE_NET_LOG_END ('e')
+#define TRACE_EVENT_PHASE_NET_LOG_INSTANT ('i')

[dsinclair, 2014/09/02 20:11:45]

I recommend against using 'i' here. We used to use 'i' for the 'I' event but it
got renamed at some point. We've been keeping 'i' free in case there are old
.trace files hanging around. The current trace-viewer will take either 'i' or
'I' as input.

[xunjieli, 2014/09/02 20:26:06]

Acknowledged.

 
 // Flags for changing the behavior of TRACE_EVENT_API_ADD_TRACE_EVENT.
 #define TRACE_EVENT_FLAG_NONE         (static_cast<unsigned char>(0))