simpleperf: Improve Callgraph.

1. Reduce columns used by callgraph by reducing spaces between
entries from 11 to 4. This helps to show more entries in the limited screen width.
2. Add [hit-in-function] line for each entry, so we know the percentage
of samples hit in the function and samples hit in the children functions.
3. Add --kallsyms option for report command.

After all, The callgraph is changed like below.
Before change:
 |--99.08%-- java.lang.Thread.run
 |           void com.example.cyb.tappydefender.TDView.run()
 |           |
 |           |           |--95.63%-- void com.example.cyb.tappydefender.TDView.draw()

After change:
 |--98.85%-- java.lang.Thread.run
 |           void com.example.cyb.tappydefender.TDView.run()
 |    |--0.09%-- [hit in function]
 |    |
 |    |--95.54%-- void com.example.cyb.tappydefender.TDView.draw()

Bug: http://b/33356538
Test: run simpleperf_unit_test.
Test: run simpleperf report -g manually.
Change-Id: Ifc1846d4ee7469cadbcc727cae6bf59552d919d5

1 files changed, 6 insertions, 0 deletions

diff --git a/simpleperf/cmd_report_test.cpp b/simpleperf/cmd_report_test.cpp
index f34be5ca..16b2f69d 100644
--- a/simpleperf/cmd_report_test.cpp
+++ b/simpleperf/cmd_report_test.cpp
@@ -437,6 +437,12 @@ TEST_F(ReportCommandTest, max_stack_and_percent_limit_option) {
   ASSERT_NE(content.find("89.03"), std::string::npos);
 }
 
+TEST_F(ReportCommandTest, kallsyms_option) {
+  Report(PERF_DATA, {"--kallsyms", GetTestData("kallsyms")});
+  ASSERT_TRUE(success);
+  ASSERT_NE(content.find("FakeKernelSymbol"), std::string::npos);
+}
+
 #if defined(__linux__)
 #include "event_selection_set.h"