Fix a DCHECK corner case. Allow (current + new == max) case....

chrome/browser/renderer_host/backing_store_manager.cc

 // Copyright (c) 2006-2008 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.
 
 #include "chrome/browser/renderer_host/backing_store_manager.h"
 
 #include "base/sys_info.h"
 #include "chrome/browser/renderer_host/backing_store.h"
 #include "chrome/browser/renderer_host/render_widget_host.h"
 #include "chrome/browser/renderer_host/render_widget_host_painting_observer.h"
@@ skipping 28 matching lines @@
 // The maximum number of large BackingStoreCache objects (tabs) to use.
 // Use a minimum of 2, and add one for each 256MB of physical memory you have.
 // Cap at 5, the thinking being that even if you have a gigantic amount of
 // RAM, there's a limit to how much caching helps beyond a certain number
 // of tabs.
 static size_t MaxNumberOfBackingStores() {
   return std::min(5, 2 + (base::SysInfo::AmountOfPhysicalMemoryMB() / 256));
 }
 
 // The maximum about of memory to use for all BackingStoreCache object combined.
-// We use this 
 static size_t MaxBackingStoreMemory() {
   // Compute in terms of the number of large monitor's worth of backing-store.
   return MaxNumberOfBackingStores() * kMemoryMultiplier;
 }
 
 // Expires the given |backing_store| from |cache|.
 void ExpireBackingStoreAt(BackingStoreCache* cache,
                           BackingStoreCache::iterator backing_store) {
   RenderWidgetHost* rwh = backing_store->second->render_widget_host();
   if (rwh->painting_observer()) {
@@ skipping 52 matching lines @@
   size_t max_mem = MaxBackingStoreMemory();
   DCHECK(new_mem < max_mem);
   if (current_mem + new_mem > max_mem) {
     // Need to remove old backing stores to make room for the new one. We
     // don't want to do this when the backing store is being replace by a new
     // one for the same tab, but this case won't get called then: we'll have
     // removed the old one in the RemoveBackingStore above, and the cache
     // won't be over-sized.
     CreateCacheSpace((current_mem + new_mem) - max_mem);
   }
-  DCHECK((BackingStoreManager::MemorySize() + new_mem) < max_mem);
+  DCHECK((BackingStoreManager::MemorySize() + new_mem) <= max_mem);
 
   BackingStoreCache* cache;
   if (new_mem > kSmallThreshold) {
     // Limit the number of large backing stores (tabs) to the memory tier number
     // (between 2-5). While we allow a larger amount of memory for people who
     // have large windows, this means that those who use small browser windows
     // won't ever cache more than 5 tabs, so they pay a smaller memory cost.
     if (large_cache->size() >= MaxNumberOfBackingStores())
       ExpireLastBackingStore(large_cache);
     cache = large_cache;
@@ skipping 104 matching lines @@
   size_t mem = 0;
   BackingStoreCache::iterator it;
   for (it = large_cache->begin(); it != large_cache->end(); ++it)
     mem += it->second->MemorySize();
 
   for (it = small_cache->begin(); it != small_cache->end(); ++it)
     mem += it->second->MemorySize();
 
   return mem;
 }