[heap] Reduce store buffer size to increase chance to run concurrent store...

[heap] Reduce store buffer size to increase chance to run concurrent store buffer processing thread more often.

BUG=

Review-Url: https://codereview.chromium.org/2529623002
Cr-Commit-Position: refs/heads/master@{#41383}

src/heap/store-buffer.h

@@ -24,7 +24,7 @@ namespace internal {
 // slots are moved to the remembered set.
 class StoreBuffer {
  public:
-  static const int kStoreBufferSize = 1 << (14 + kPointerSizeLog2);
+  static const int kStoreBufferSize = 1 << (11 + kPointerSizeLog2);
   static const int kStoreBufferMask = kStoreBufferSize - 1;
   static const int kStoreBuffers = 2;
   static const intptr_t kDeletionTag = 1;