Fix more -Wsign-compare warnings in heap, mips, base, etc.

test/cctest/libplatform/test-tracing.cc

Index: test/cctest/libplatform/test-tracing.cc
diff --git a/test/cctest/libplatform/test-tracing.cc b/test/cctest/libplatform/test-tracing.cc
index 46eb6a93ad1fd48dc25fb96451fa31456ae0de52..6189ed2dfc6df375f056ba1da3879e9af3bd2d18 100644
--- a/test/cctest/libplatform/test-tracing.cc
+++ b/test/cctest/libplatform/test-tracing.cc
@@ -38,8 +38,8 @@ TEST(TestTraceObject) {
   CHECK_EQ(category_enabled_flag, *trace_object.category_enabled_flag());
   CHECK_EQ(std::string("Test.Trace"), std::string(trace_object.name()));
   CHECK_EQ(std::string("Test.Scope"), std::string(trace_object.scope()));
-  CHECK_EQ(0, trace_object.duration());
-  CHECK_EQ(0, trace_object.cpu_duration());
+  CHECK_EQ(0u, trace_object.duration());
+  CHECK_EQ(0u, trace_object.cpu_duration());
 }
 
 class ConvertableToTraceFormatMock : public v8::ConvertableToTraceFormat {
@@ -186,7 +186,7 @@ TEST(TestTracingController) {
   TRACE_EVENT0("v8", "v8.Test3");
   tracing_controller.StopTracing();
 
-  CHECK_EQ(2, writer->events().size());
+  CHECK_EQ(2u, writer->events().size());
   CHECK_EQ(std::string("v8.Test"), writer->events()[0]);
   CHECK_EQ(std::string("v8.Test3"), writer->events()[1]);
 
@@ -294,7 +294,7 @@ TEST(TestTracingControllerMultipleArgsAndCopy) {
   GetJSONStrings(all_names, trace_str, "\"name\"", "\"", "\"");
   GetJSONStrings(all_cats, trace_str, "\"cat\"", "\"", "\"");
 
-  CHECK_EQ(all_args.size(), 24);
+  CHECK_EQ(all_args.size(), 24u);
   CHECK_EQ(all_args[0], "\"aa\":11");
   CHECK_EQ(all_args[1], "\"bb\":22");
   CHECK_EQ(all_args[2], "\"cc\":33");