Add granular file tracing.

base/trace_event/trace_event.h

Index: base/trace_event/trace_event.h
diff --git a/base/trace_event/trace_event.h b/base/trace_event/trace_event.h
index d4e8070b8f1420a43657fcbc686cb579040deb20..2c30b3340a2dd06edf8fcd8290ef96eee0412b16 100644
--- a/base/trace_event/trace_event.h
+++ b/base/trace_event/trace_event.h
@@ -716,27 +716,43 @@
 // NESTABLE_ASYNC event of that id. Corresponding warning messages for
 // unmatched events will be shown in the analysis view.
 
-// Records a single NESTABLE_ASYNC_BEGIN event called "name" immediately, with 2
-// associated arguments. If the category is not enabled, then this does nothing.
+// Records a single NESTABLE_ASYNC_BEGIN event called "name" immediately, with
+// 0, 1 or 2 associated arguments. If the category is not enabled, then this
+// does nothing.
+#define TRACE_EVENT_NESTABLE_ASYNC_BEGIN0(category_group, name, id) \
+    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_NESTABLE_ASYNC_BEGIN, \
+        category_group, name, id, TRACE_EVENT_FLAG_NONE)
+#define TRACE_EVENT_NESTABLE_ASYNC_BEGIN1(category_group, name, id, arg1_name, \
+        arg1_val) \
+    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_NESTABLE_ASYNC_BEGIN, \
+        category_group, name, id, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val)
 #define TRACE_EVENT_NESTABLE_ASYNC_BEGIN2(category_group, name, id, arg1_name, \
         arg1_val, arg2_name, arg2_val) \
     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_NESTABLE_ASYNC_BEGIN, \
         category_group, name, id, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val, \
         arg2_name, arg2_val)
+// Records a single NESTABLE_ASYNC_END event called "name" immediately, with 0,
+// 1, or 2 associated arguments. If the category is not enabled, then this does
+// nothing.
+#define TRACE_EVENT_NESTABLE_ASYNC_END0(category_group, name, id) \
+    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_NESTABLE_ASYNC_END, \
+        category_group, name, id, TRACE_EVENT_FLAG_NONE)
+#define TRACE_EVENT_NESTABLE_ASYNC_END1(category_group, name, id, arg1_name, \
+        arg1_val) \
+    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_NESTABLE_ASYNC_END, \
+        category_group, name, id, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val)
+#define TRACE_EVENT_NESTABLE_ASYNC_END2(category_group, name, id, arg1_name, \
+        arg1_val, arg2_name, arg2_val) \
+    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_NESTABLE_ASYNC_END, \
+        category_group, name, id, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val, \
+        arg2_name, arg2_val)
+
 #define TRACE_EVENT_COPY_NESTABLE_ASYNC_BEGIN_WITH_TTS2(category_group, name, \
         id, arg1_name, arg1_val, arg2_name, arg2_val) \
     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_NESTABLE_ASYNC_BEGIN, \
         category_group, name, id, \
         TRACE_EVENT_FLAG_ASYNC_TTS | TRACE_EVENT_FLAG_COPY, \
         arg1_name, arg1_val, arg2_name, arg2_val)
-
-// Records a single NESTABLE_ASYNC_END event called "name" immediately, with 2
-// associated arguments. If the category is not enabled, then this does nothing.
-#define TRACE_EVENT_NESTABLE_ASYNC_END2(category_group, name, id, arg1_name, \
-        arg1_val, arg2_name, arg2_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_NESTABLE_ASYNC_END, \
-        category_group, name, id, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val, \
-        arg2_name, arg2_val)
 #define TRACE_EVENT_COPY_NESTABLE_ASYNC_END_WITH_TTS2(category_group, name, \
         id, arg1_name, arg1_val, arg2_name, arg2_val) \
     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_NESTABLE_ASYNC_END, \