cc: Free gpu resources when we are invisible or TM is oom.

cc/resources/tile_manager.cc

 // Copyright 2012 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 "cc/resources/tile_manager.h"
 
 #include <algorithm>
 #include <limits>
 #include <string>
 
@@ skipping 621 matching lines @@
             priority, &memory_usage);
     bool memory_usage_is_within_limit =
         !memory_usage.Exceeds(scheduled_tile_memory_limit);
 
     // If we couldn't fit the tile into our current memory limit, then we're
     // done.
     if (!memory_usage_is_within_limit) {
       if (tile_is_needed_now)
         had_enough_memory_to_schedule_tiles_needed_now = false;
       all_tiles_that_need_to_be_rasterized_are_scheduled_ = false;
+      // OOM, clear cache (applicable in gpu-raster case)
+      rasterizer_->ClearCache();

[sohanjg, 2015/03/17 11:20:18]

Will this be the only place to clear cache when OOM ?

[vmiura, 2015/03/19 21:20:35]

I don't think this is the OOM condition where we should clear the cache.

What I think we want is that we clear the cache when TileManager's hard memory
policy changes to 0 bytes.

[sohanjg, 2015/03/23 10:34:38]

Acknowledged.

[vmiura, 2015/03/23 20:34:39]

I'm not sure this is actually what we want to do.

What I think we want is that we clear the Ganesh cache when TileManager hard
memory limit is reduced to 0.

vmpstr@ could you provide some guidance?

       break;
     }
 
     memory_usage += memory_required_by_tile_to_be_scheduled;
     tiles_that_need_to_be_rasterized->push_back(tile);
   }
 
   // Note that we should try and further reduce memory in case the above loop
   // didn't reduce memory. This ensures that we always release as many resources
   // as possible to stay within the memory limit.
@@ skipping 396 matching lines @@
   result -= other;
   return result;
 }
 
 bool TileManager::MemoryUsage::Exceeds(const MemoryUsage& limit) const {
   return memory_bytes_ > limit.memory_bytes_ ||
          resource_count_ > limit.resource_count_;
 }
 
 }  // namespace cc