Merge bleeding edge up to 9192 into the GC branch.

src/objects-debug.cc

Index: src/objects-debug.cc
diff --git a/src/objects-debug.cc b/src/objects-debug.cc
index a14b5e7937d28663bf8c612e0a2b65714f4b8b73..1670a8b6707bd5af63769ba8509c7e40b296352a 100644
--- a/src/objects-debug.cc
+++ b/src/objects-debug.cc
@@ -265,9 +265,9 @@ void JSObject::JSObjectVerify() {
              (map()->inobject_properties() + properties()->length() -
               map()->NextFreePropertyIndex()));
   }
-  ASSERT(map()->has_fast_elements() ==
-         (elements()->map() == GetHeap()->fixed_array_map() ||
-          elements()->map() == GetHeap()->fixed_cow_array_map()));
+  ASSERT_EQ(map()->has_fast_elements(),
+            (elements()->map() == GetHeap()->fixed_array_map() ||
+             elements()->map() == GetHeap()->fixed_cow_array_map()));
   ASSERT(map()->has_fast_elements() == HasFastElements());
 }
 
@@ -360,6 +360,31 @@ void String::StringVerify() {
   if (IsSymbol()) {
     CHECK(!HEAP->InNewSpace(this));
   }
+  if (IsConsString()) {
+    ConsString::cast(this)->ConsStringVerify();
+  } else if (IsSlicedString()) {
+    SlicedString::cast(this)->SlicedStringVerify();
+  }
+}
+
+
+void ConsString::ConsStringVerify() {
+  CHECK(this->first()->IsString());
+  CHECK(this->second() == GetHeap()->empty_string() ||
+        this->second()->IsString());
+  CHECK(this->length() >= String::kMinNonFlatLength);
+  if (this->IsFlat()) {
+    // A flat cons can only be created by String::SlowTryFlatten.
+    // Afterwards, the first part may be externalized.
+    CHECK(this->first()->IsSeqString() || this->first()->IsExternalString());
+  }
+}
+
+
+void SlicedString::SlicedStringVerify() {
+  CHECK(!this->parent()->IsConsString());
+  CHECK(!this->parent()->IsSlicedString());
+  CHECK(this->length() >= SlicedString::kMinLength);
 }