Reverts CLs related to the TLAB due to heap exhaustion.

runtime/vm/scavenger.h

Index: runtime/vm/scavenger.h
diff --git a/runtime/vm/scavenger.h b/runtime/vm/scavenger.h
index de6d01f9712af815797e8981b5dcaafbe9e38277..1fd7c9fe2bd88b93e8f26e2c6b7964e11a0408bc 100644
--- a/runtime/vm/scavenger.h
+++ b/runtime/vm/scavenger.h
@@ -121,25 +121,6 @@ class Scavenger {
 
   RawObject* FindObject(FindObjectVisitor* visitor) const;
 
-  uword TryAllocateNewTLAB(Thread* thread, intptr_t size) {
-    ASSERT(Utils::IsAligned(size, kObjectAlignment));
-    ASSERT(heap_ != Dart::vm_isolate()->heap());
-    ASSERT(!scavenging_);
-    uword result = top_;
-    intptr_t remaining = end_ - top_;
-    if (remaining < size) {
-      return 0;
-    }
-    ASSERT(to_->Contains(result));
-    ASSERT((result & kObjectAlignmentMask) == object_alignment_);
-    top_ += size;
-    ASSERT(to_->Contains(top_) || (top_ == to_->end()));
-    ASSERT(result < top_);
-    thread->set_top(result);
-    thread->set_end(top_);
-    return result;
-  }
-
   uword AllocateGC(intptr_t size) {
     ASSERT(Utils::IsAligned(size, kObjectAlignment));
     ASSERT(heap_ != Dart::vm_isolate()->heap());
@@ -153,7 +134,7 @@ class Scavenger {
     ASSERT(to_->Contains(result));
     ASSERT((result & kObjectAlignmentMask) == object_alignment_);
     top_ += size;
-    ASSERT((to_->Contains(top_)) || (top_ == to_->end()));
+    ASSERT(to_->Contains(top_) || (top_ == to_->end()));
     return result;
   }
 
@@ -162,8 +143,6 @@ class Scavenger {
     ASSERT(heap_ != Dart::vm_isolate()->heap());
     ASSERT(thread->IsMutatorThread());
     ASSERT(thread->isolate()->IsMutatorThreadScheduled());
-    ASSERT(thread->top() <= top_);
-    ASSERT((thread->end() == 0) || (thread->end() == top_));
 #if defined(DEBUG)
     if (FLAG_gc_at_alloc) {
       ASSERT(!scavenging_);
@@ -180,7 +159,7 @@ class Scavenger {
     ASSERT(to_->Contains(result));
     ASSERT((result & kObjectAlignmentMask) == object_alignment_);
     top += size;
-    ASSERT((to_->Contains(top)) || (top == to_->end()));
+    ASSERT(to_->Contains(top) || (top == to_->end()));
     thread->set_top(top);
     return result;
   }
@@ -201,7 +180,9 @@ class Scavenger {
     end_ = value;
   }
 
-  int64_t UsedInWords() const;
+  int64_t UsedInWords() const {
+    return (top_ - FirstObjectStart()) >> kWordSizeLog2;
+  }
   int64_t CapacityInWords() const { return to_->size_in_words(); }
   int64_t ExternalInWords() const { return external_size_ >> kWordSizeLog2; }
   SpaceUsage GetCurrentUsage() const {
@@ -234,8 +215,7 @@ class Scavenger {
   void AllocateExternal(intptr_t size);
   void FreeExternal(intptr_t size);
 
-  void MakeNewSpaceIterable() const;
-  uword FirstObjectStart() const { return to_->start() | object_alignment_; }
+  void FlushTLS() const;
 
  private:
   // Ids for time and data records in Heap::GCStats.
@@ -254,6 +234,7 @@ class Scavenger {
     kToKBAfterStoreBuffer = 3
   };
 
+  uword FirstObjectStart() const { return to_->start() | object_alignment_; }
   SemiSpace* Prologue(Isolate* isolate, bool invoke_api_callbacks);
   void IterateStoreBuffers(Isolate* isolate, ScavengerVisitor* visitor);
   void IterateObjectIdTable(Isolate* isolate, ScavengerVisitor* visitor);