CPU profiler: increase the max number of captured frames.

test/cctest/test-cpu-profiler.cc

Index: test/cctest/test-cpu-profiler.cc
diff --git a/test/cctest/test-cpu-profiler.cc b/test/cctest/test-cpu-profiler.cc
index 77b5bd877c7e8d6a688eed341ca18965e6f90163..6f6621fc81521ce63b783f8279955a479f8b9ecf 100644
--- a/test/cctest/test-cpu-profiler.cc
+++ b/test/cctest/test-cpu-profiler.cc
@@ -283,7 +283,7 @@ TEST(Issue1398) {
   sample->pc = code->address();
   sample->tos = 0;
   sample->frames_count = i::TickSample::kMaxFramesCount;
-  for (int i = 0; i < sample->frames_count; ++i) {
+  for (unsigned i = 0; i < sample->frames_count; ++i) {
     sample->stack[i] = code->address();
   }
   processor->FinishTickSample();