content: Close in-process discardable memory segments.

content/common/host_discardable_shared_memory_manager.cc

Index: content/common/host_discardable_shared_memory_manager.cc
diff --git a/content/common/host_discardable_shared_memory_manager.cc b/content/common/host_discardable_shared_memory_manager.cc
index 99db11720c7c9665d133291f2e691d8b848036d2..d2c210e54ed78e08a222296e5f3b7abcd0818f10 100644
--- a/content/common/host_discardable_shared_memory_manager.cc
+++ b/content/common/host_discardable_shared_memory_manager.cc
@@ -123,6 +123,8 @@ HostDiscardableSharedMemoryManager::AllocateLockedDiscardableMemory(
   scoped_ptr<base::DiscardableSharedMemory> memory(
       new base::DiscardableSharedMemory(handle));
   CHECK(memory->Map(size));
+  // Close file descriptor to avoid running out.
+  memory->Close();
   return make_scoped_ptr(new DiscardableMemoryImpl(
       memory.Pass(),
       base::Bind(
@@ -237,6 +239,11 @@ void HostDiscardableSharedMemoryManager::AllocateLockedDiscardableSharedMemory(
   bytes_allocated_ = checked_bytes_allocated.ValueOrDie();
   BytesAllocatedChanged(bytes_allocated_);
 
+#if !defined(DISCARDABLE_SHARED_MEMORY_SHRINKING)
+  // Close file descriptor to avoid running out.
+  memory->Close();
+#endif
+
   scoped_refptr<MemorySegment> segment(new MemorySegment(memory.Pass()));
   process_segments[id] = segment.get();
   segments_.push_back(segment.get());
@@ -365,6 +372,7 @@ void HostDiscardableSharedMemoryManager::ReleaseMemory(
   // Note: We intentionally leave the segment in the |segments| vector to
   // avoid reconstructing the heap. The element will be removed from the heap
   // when its last usage time is older than all other segments.
+  memory->Unmap();
   memory->Close();
 }