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

test/unittests/heap/gc-tracer-unittest.cc

Index: test/unittests/heap/gc-tracer-unittest.cc
diff --git a/test/unittests/heap/gc-tracer-unittest.cc b/test/unittests/heap/gc-tracer-unittest.cc
index 9c49827d421efb58a12195071eafd4e2802e72aa..e7702fda757077dc32ddf9b17738544709a63485 100644
--- a/test/unittests/heap/gc-tracer-unittest.cc
+++ b/test/unittests/heap/gc-tracer-unittest.cc
@@ -263,7 +263,7 @@ TEST_F(GCTracerTest, IncrementalMarkingSpeed) {
   // 1000000 bytes in 100ms.
   tracer->AddIncrementalMarkingStep(100, 1000000);
   EXPECT_EQ(300, tracer->incremental_marking_duration_);
-  EXPECT_EQ(3000000, tracer->incremental_marking_bytes_);
+  EXPECT_EQ(3000000u, tracer->incremental_marking_bytes_);
   EXPECT_EQ(1000000 / 100,
             tracer->IncrementalMarkingSpeedInBytesPerMillisecond());
   tracer->Start(MARK_COMPACTOR, GarbageCollectionReason::kTesting,
@@ -273,12 +273,12 @@ TEST_F(GCTracerTest, IncrementalMarkingSpeed) {
   // 1000000 bytes in 100ms.
   tracer->AddIncrementalMarkingStep(100, 1000000);
   EXPECT_EQ(400, tracer->incremental_marking_duration_);
-  EXPECT_EQ(4000000, tracer->incremental_marking_bytes_);
+  EXPECT_EQ(4000000u, tracer->incremental_marking_bytes_);
   tracer->Stop(MARK_COMPACTOR);
   EXPECT_EQ(400, tracer->current_.incremental_marking_duration);
-  EXPECT_EQ(4000000, tracer->current_.incremental_marking_bytes);
+  EXPECT_EQ(4000000u, tracer->current_.incremental_marking_bytes);
   EXPECT_EQ(0, tracer->incremental_marking_duration_);
-  EXPECT_EQ(0, tracer->incremental_marking_bytes_);
+  EXPECT_EQ(0u, tracer->incremental_marking_bytes_);
   EXPECT_EQ(1000000 / 100,
             tracer->IncrementalMarkingSpeedInBytesPerMillisecond());