Increase external allocation limit.

BUG=
R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/291653005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21425 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap.cc

@@ -5052,9 +5052,8 @@ bool Heap::ConfigureHeap(int max_semi_space_size,
   initial_semispace_size_ = Min(initial_semispace_size_, max_semi_space_size_);
 
   // The external allocation limit should be below 256 MB on all architectures
-  // to avoid unnecessary low memory notifications, as that is the threshold
-  // for some embedders.
-  external_allocation_limit_ = 12 * max_semi_space_size_;
+  // to avoid that resource-constrained embedders run low on memory.
+  external_allocation_limit_ = 192 * MB;
   ASSERT(external_allocation_limit_ <= 256 * MB);
 
   // The old generation is paged and needs at least one page for each space.