tree 9f2b3c0bfbfef5c9ccb8525beff216eb40bf1848
parent 14d27a46be7ec589a1be5e3a20731e3492a49278
author Vincent Rabaud <vrabaud@google.com> 1449742100 +0100
committer Vincent Rabaud <vrabaud@google.com> 1449747851 +0100

Optimize the heap usage in HistogramCombineGreedy.

The previous priority system used a heap which was too heavy to
maintain (what was gained from insertions / deletions was lost
due to a linear that still happened on the heap for invalidation).
The new structure is a priority queue where only the head is
ordered.

Change-Id: Id13f8694885a934fe2b2f115f8f84ada061b9016