Upstream android file related code.

base/shared_memory.h

 // Copyright (c) 2011 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.
 
 #ifndef BASE_SHARED_MEMORY_H_
 #define BASE_SHARED_MEMORY_H_
 #pragma once
 
 #include "build/build_config.h"
 
@@ skipping 166 matching lines @@
   // A Lock() implementation with a timeout that also allows setting
   // security attributes on the mutex. sec_attr may be NULL.
   // Returns true if the Lock() has been acquired, false if the timeout was
   // reached.
   bool Lock(uint32 timeout_ms, SECURITY_ATTRIBUTES* sec_attr);
 #endif
 
   // Releases the shared memory lock.
   void Unlock();
 
+#if defined(OS_ANDROID)
+  // Returns the size of shared memory or a negative value on error.
+  int GetAshmenSizeRegion();

[darin (slow to review), 2011/06/21 18:44:02]

I am still wondering why you need this method.  If the goal of
http://code.google.com/p/chromium/issues/detail?id=60821 is to hide knowledge of
the size, then the addition of this method here seems to be going against that
goal.

+#endif
+
  private:
 #if defined(OS_POSIX)
   bool PrepareMapFile(FILE *fp);
   bool FilePathForMemoryName(const std::string& mem_name, FilePath* path);
   void LockOrUnlockCommon(int function);
 #endif
   bool ShareToProcessCommon(ProcessHandle process,
                             SharedMemoryHandle* new_handle,
                             bool close_self);
 
@@ skipping 29 matching lines @@
   }
 
  private:
   SharedMemory* shared_memory_;
   DISALLOW_COPY_AND_ASSIGN(SharedMemoryAutoLock);
 };
 
 }  // namespace base
 
 #endif  // BASE_SHARED_MEMORY_H_