Perform scavenges only for small idle times.

BUG=
R=jochen@chromium.org

Review URL: https://codereview.chromium.org/586643002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24066 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap/gc-idle-time-handler.cc

@@ -110,7 +110,8 @@ bool GCIdleTimeHandler::ScavangeMayHappenSoon(
 // that this currently may trigger a full garbage collection.
 GCIdleTimeAction GCIdleTimeHandler::Compute(size_t idle_time_in_ms,
                                             HeapState heap_state) {
-  if (ScavangeMayHappenSoon(
+  if (idle_time_in_ms <= kMaxFrameRenderingIdleTime &&
+      ScavangeMayHappenSoon(
           heap_state.available_new_space_memory,
           heap_state.new_space_allocation_throughput_in_bytes_per_ms) &&
       idle_time_in_ms >=