content: Close in-process discardable memory segments.

base/memory/discardable_shared_memory.h

Index: base/memory/discardable_shared_memory.h
diff --git a/base/memory/discardable_shared_memory.h b/base/memory/discardable_shared_memory.h
index 892d556471ed85afa2d50f30553a097461624eca..74bbe8e95f427ba347d696e6c6e9c408e166e167 100644
--- a/base/memory/discardable_shared_memory.h
+++ b/base/memory/discardable_shared_memory.h
@@ -48,6 +48,11 @@ class BASE_EXPORT DiscardableSharedMemory {
   // Returns true on success, false otherwise.
   bool Map(size_t size);
 
+  // Unmaps the discardable shared memory from the caller's address space.
+  // Returns true if successful; returns false on error or if the memory is
+  // not mapped.
+  bool Unmap();
+
   // The actual size of the mapped memory (may be larger than requested).
   size_t mapped_size() const { return mapped_size_; }