Adding discardable memory dump provider.

content/common/discardable_shared_memory_heap_perftest.cc

Index: content/common/discardable_shared_memory_heap_perftest.cc
diff --git a/content/common/discardable_shared_memory_heap_perftest.cc b/content/common/discardable_shared_memory_heap_perftest.cc
index 566f094b94f933b510ecd25f0aa31bfcce737ab6..304f3bf67a961d99484f6e7af6f49fadaa08e4fc 100644
--- a/content/common/discardable_shared_memory_heap_perftest.cc
+++ b/content/common/discardable_shared_memory_heap_perftest.cc
@@ -38,7 +38,7 @@ TEST(DiscardableSharedMemoryHeapTest, SearchFreeLists) {
         new base::DiscardableSharedMemory);
     ASSERT_TRUE(memory->CreateAndMap(segment_size));
     heap.MergeIntoFreeLists(
-        heap.Grow(memory.Pass(), segment_size, base::Bind(NullTask)).Pass());
+        heap.Grow(memory.Pass(), segment_size, 0, base::Bind(NullTask)).Pass());

[picksi, 2015/04/29 15:30:15]

Is 0 a special ID? Can we pass it as a named static ("kDefaultMemoryID"?) ... I
had to find the function definition to understand what this 0 was.

This is passed on to a lower level function; is there anything inside that
function that defines '0'? If so let's use that.

[reveman, 2015/04/29 15:40:29]

Maybe just add a next_discardable_shared_memory_id variable that we increment

   }
 
   unsigned kSeed = 1;