Change invalid root from LOG(ERROR) to LOG(INTERNAL_FATAL)

INTERNAL_FATAL is more likely to remain in bug reports.

Bug: 20736048
Change-Id: I518f079d8d1839e22b3595e807730edf36318f1d
diff --git a/runtime/gc/collector/mark_sweep.cc b/runtime/gc/collector/mark_sweep.cc
index f0e8d14..c6d2861 100644
--- a/runtime/gc/collector/mark_sweep.cc
+++ b/runtime/gc/collector/mark_sweep.cc
@@ -381,8 +381,8 @@
     if (UNLIKELY(obj == nullptr || !IsAligned<kPageSize>(obj) ||
                  (kIsDebugBuild && large_object_space != nullptr &&
                      !large_object_space->Contains(obj)))) {
-      LOG(ERROR) << "Tried to mark " << obj << " not contained by any spaces";
-      LOG(ERROR) << "Attempting see if it's a bad root";
+      LOG(INTERNAL_FATAL) << "Tried to mark " << obj << " not contained by any spaces";
+      LOG(INTERNAL_FATAL) << "Attempting see if it's a bad root";
       mark_sweep_->VerifyRoots();
       LOG(FATAL) << "Can't mark invalid object";
     }
@@ -498,7 +498,7 @@
     if (heap->GetLiveBitmap()->GetContinuousSpaceBitmap(root) == nullptr) {
       space::LargeObjectSpace* large_object_space = heap->GetLargeObjectsSpace();
       if (large_object_space != nullptr && !large_object_space->Contains(root)) {
-        LOG(ERROR) << "Found invalid root: " << root << " " << info;
+        LOG(INTERNAL_FATAL) << "Found invalid root: " << root << " " << info;
       }
     }
   }