tracing: export ProcessDescriptor and TrackDescriptor proto headers

These can be used by SDK users without relying on headers that might
have restricted visibility in Bazel.

Change-Id: I47fe5671a27cd61a6091ff0f22848b02ee27cba5

include/perfetto/tracing/track.h

@@ -26,11 +26,15 @@
 #include "perfetto/tracing/internal/tracing_muxer.h"
 #include "perfetto/tracing/platform.h"
 #include "perfetto/tracing/string_helpers.h"
-#include "protos/perfetto/trace/trace_packet.pbzero.h"
-#include "protos/perfetto/trace/track_event/counter_descriptor.gen.h"
-#include "protos/perfetto/trace/track_event/counter_descriptor.pbzero.h"
-#include "protos/perfetto/trace/track_event/track_descriptor.gen.h"
-#include "protos/perfetto/trace/track_event/track_descriptor.pbzero.h"
+#include "protos/perfetto/trace/trace_packet.pbzero.h"  // IWYU pragma: export
+#include "protos/perfetto/trace/track_event/counter_descriptor.gen.h"  // IWYU pragma: export
+#include "protos/perfetto/trace/track_event/counter_descriptor.pbzero.h"  // IWYU pragma: export
+#include "protos/perfetto/trace/track_event/process_descriptor.gen.h"  // IWYU pragma: export
+#include "protos/perfetto/trace/track_event/process_descriptor.pbzero.h"  // IWYU pragma: export
+#include "protos/perfetto/trace/track_event/thread_descriptor.gen.h"  // IWYU pragma: export
+#include "protos/perfetto/trace/track_event/thread_descriptor.pbzero.h"  // IWYU pragma: export
+#include "protos/perfetto/trace/track_event/track_descriptor.gen.h"  // IWYU pragma: export
+#include "protos/perfetto/trace/track_event/track_descriptor.pbzero.h"  // IWYU pragma: export
 
 #include <stdint.h>
 #include <map>