perf report: Add a simple GTK2-based 'perf report' browser

This patch adds a simple GTK2-based browser to 'perf report' that's
based on the TTY-based browser in builtin-report.c.

To launch "perf report" using the new GTK interface just type:

  $ perf report --gtk

The interface is somewhat limited in features at the moment:

  - No callgraph support

  - No KVM guest profiling support

  - No color coding for percentages

  - No sorting from the UI

  - ..and many, many more!

That said, I think this patch a reasonable start to build future features on.

Signed-off-by: Pekka Enberg <penberg@kernel.org>
Cc: Colin Walters <walters@verbum.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1202231952410.6689@tux.localdomain
[ committer note: Added #pragma to make gtk no strict prototype problem go
  away as suggested by Colin Walters modulo avoiding push/pop ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/hist.h

@@ -147,6 +147,23 @@ int perf_evlist__tui_browse_hists(struct perf_evlist *evlist, const char *help,
 				  int refresh);
 #endif
 
+#ifdef NO_GTK2_SUPPORT
+static inline
+int perf_evlist__gtk_browse_hists(struct perf_evlist *evlist __used,
+				  const char *help __used,
+				  void(*timer)(void *arg) __used,
+				  void *arg __used,
+				  int refresh __used)
+{
+	return 0;
+}
+
+#else
+int perf_evlist__gtk_browse_hists(struct perf_evlist *evlist, const char *help,
+				  void(*timer)(void *arg), void *arg,
+				  int refresh);
+#endif
+
 unsigned int hists__sort_list_width(struct hists *self);
 
 #endif	/* __PERF_HIST_H */