[heap] Remove old_gen_exhausted_ state.

The AllocationResult already carries the information in which space the allocation failure happened.
BUG=

Review-Url: https://codereview.chromium.org/2333293002
Cr-Commit-Position: refs/heads/master@{#39387}

src/heap/heap-inl.h

@@ -365,8 +365,6 @@ AllocationResult Heap::AllocateRaw(int size_in_bytes, AllocationSpace space,
   }
   if (allocation.To(&object)) {
     OnAllocationEvent(object, size_in_bytes);
-  } else {
-    old_gen_exhausted_ = true;
   }
 
   return allocation;

src/heap/heap.cc

@@ -112,7 +112,6 @@ Heap::Heap()
       allocation_timeout_(0),
 #endif  // DEBUG
       old_generation_allocation_limit_(initial_old_generation_size_),
-      old_gen_exhausted_(false),
       inline_allocation_disabled_(false),
       total_regexp_code_generated_(0),
       tracer_(nullptr),
@@ -282,15 +281,6 @@ GarbageCollector Heap::SelectGarbageCollector(AllocationSpace space,
     return MARK_COMPACTOR;
   }
 
-  // Have allocation in OLD and LO failed?
-  if (old_gen_exhausted_) {
-    isolate_->counters()
-        ->gc_compactor_caused_by_oldspace_exhaustion()
-        ->Increment();
-    *reason = "old generations exhausted";
-    return MARK_COMPACTOR;
-  }
-
   // Is there enough space left in OLD to guarantee that a scavenge can
   // succeed?
   //
@@ -1341,7 +1331,6 @@ bool Heap::PerformGarbageCollection(
       UpdateOldGenerationAllocationCounter();
       // Perform mark-sweep with optional compaction.
       MarkCompact();
-      old_gen_exhausted_ = false;
       old_generation_size_configured_ = true;
       // This should be updated before PostGarbageCollectionProcessing, which
       // can cause another GC. Take into account the objects promoted during GC.

src/heap/heap.h

@@ -2154,10 +2154,6 @@ class Heap {
   // generation and on every allocation in large object space.
   intptr_t old_generation_allocation_limit_;
 
-  // Indicates that an allocation has failed in the old generation since the
-  // last GC.
-  bool old_gen_exhausted_;
-
   // Indicates that inline bump-pointer allocation has been globally disabled
   // for all spaces. This is used to disable allocations in generated code.
   bool inline_allocation_disabled_;