Fix numerous bugs introduced by reducing Page::kMaxHeapObjectSize.

src/spaces.h

Index: src/spaces.h
diff --git a/src/spaces.h b/src/spaces.h
index 4d4ef4be7ee4c656e5d915cd25db2bd7e5806456..ec64e6e98d13797d0c8274e9df1e4bba5a5db651 100644
--- a/src/spaces.h
+++ b/src/spaces.h
@@ -314,7 +314,10 @@ class Page : public MemoryChunk {
   static const int kObjectAreaSize = kPageSize - kObjectStartOffset;
 
   // Maximum object size that fits in a page.
-  static const int kMaxHeapObjectSize = kObjectAreaSize >> 4;
+  static const int kMaxHeapObjectSize =
+    OBJECT_POINTER_ALIGN(kObjectAreaSize >> 4);
+
+  STATIC_ASSERT((kMaxHeapObjectSize & kObjectAlignmentMask) == 0);
 
 #ifdef ENABLE_CARDMARKING_WRITE_BARRIER
   static const int kDirtyFlagOffset = 2 * kPointerSize;
@@ -1738,6 +1741,24 @@ class OldSpace : public PagedSpace {
     return page->ObjectAreaEnd();
   }
 
+  void AddToFreeList(Address start, int size_in_bytes) {
+    // TODO(gc) instead of putting large chunks into free list try to
+    // reuse them for linear allocation.
+    int wasted_bytes = 0;
+
+    while (size_in_bytes >= Page::kMaxHeapObjectSize) {
+      wasted_bytes += free_list_.Free(start, Page::kMaxHeapObjectSize);
+      start += Page::kMaxHeapObjectSize;
+      size_in_bytes -= Page::kMaxHeapObjectSize;
+    }
+
+    if (size_in_bytes > 0) {
+      wasted_bytes += free_list_.Free(start, size_in_bytes);
+    }
+
+    accounting_stats_.WasteBytes(wasted_bytes);
+  }
+
   // Give a block of memory to the space's free list.  It might be added to
   // the free list or accounted as waste.
   // If add_to_freelist is false then just accounting stats are updated and
@@ -1745,10 +1766,7 @@ class OldSpace : public PagedSpace {
   void Free(Address start, int size_in_bytes, bool add_to_freelist) {
     accounting_stats_.DeallocateBytes(size_in_bytes);
 
-    if (add_to_freelist) {
-      int wasted_bytes = free_list_.Free(start, size_in_bytes);
-      accounting_stats_.WasteBytes(wasted_bytes);
-    }
+    if (add_to_freelist) AddToFreeList(start, size_in_bytes);
   }
 
   virtual void DeallocateBlock(Address start,