Calling LowerInlineAllocationLimit from the bottom of Heap::Scavenge seems to be
a no-op.

  new_space_.LowerInlineAllocationLimit(
      new_space_.inline_allocation_limit_step());

LowerInlineAllocatoinLimit does the following things:

1. Set the inline_allocation_limit_step_ to the passed in value. No-op.
2. Calls UpdateInlineAllocationLimit(0). This is unnecessary here as it has
   already been called when new_space_.ResetAllocationInfo was called above.
3. Sets top_on_previous_step_. This again is unnecessary as it gets reached by
   ResetAllocationInfo as well.

BUG=
R=hpayer@chromium.org,ulan@chromium.org

Review URL: https://codereview.chromium.org/1390013002

Cr-Commit-Position: refs/heads/master@{#31156}