Add GLES2Implemention::FreeUnusedSharedMemory

gpu/command_buffer/client/fenced_allocator.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file contains the implementation of the FencedAllocator class.
 
 #include "../client/fenced_allocator.h"
 #include <algorithm>
 #include "../client/cmd_buffer_helper.h"
 
@@ skipping 112 matching lines @@
     if (next.offset <= current.offset)
       return false;
     if (next.offset != current.offset + current.size)
       return false;
     if (current.state == FREE && next.state == FREE)
       return false;
   }
   return true;
 }
 
+bool FencedAllocator::InUse() {
+  return blocks_.size() != 1 || blocks_[0].state != FREE;
+}
+
 // Collapse the block to the next one, then to the previous one. Provided the
 // structure is consistent, those are the only blocks eligible for collapse.
 FencedAllocator::BlockIndex FencedAllocator::CollapseFreeBlock(
     BlockIndex index) {
   if (index + 1 < blocks_.size()) {
     Block &next = blocks_[index + 1];
     if (next.state == FREE) {
       blocks_[index].size += next.size;
       blocks_.erase(blocks_.begin() + index + 1);
     }
@@ skipping 56 matching lines @@
 // The blocks are in offset order, so we can do a binary search.
 FencedAllocator::BlockIndex FencedAllocator::GetBlockByOffset(Offset offset) {
   Block templ = { IN_USE, offset, 0, kUnusedToken };
   Container::iterator it = std::lower_bound(blocks_.begin(), blocks_.end(),
                                             templ, OffsetCmp());
   GPU_DCHECK(it != blocks_.end() && it->offset == offset);
   return it-blocks_.begin();
 }
 
 }  // namespace gpu