PPAPI: Implement PPB_FileMapping on POSIX

ppapi/proxy/file_io_resource.h

 // Copyright (c) 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.
 
 #ifndef PPAPI_PROXY_FILE_IO_RESOURCE_H_
 #define PPAPI_PROXY_FILE_IO_RESOURCE_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
@@ skipping 50 matching lines @@
   virtual int64_t GetAppendModeWriteAmount() const OVERRIDE;
   virtual void SetMaxWrittenOffset(int64_t max_written_offset) OVERRIDE;
   virtual void SetAppendModeWriteAmount(
       int64_t append_mode_write_amount) OVERRIDE;
   virtual int32_t Flush(scoped_refptr<TrackedCallback> callback) OVERRIDE;
   virtual void Close() OVERRIDE;
   virtual int32_t RequestOSFileHandle(
       PP_FileHandle* handle,
       scoped_refptr<TrackedCallback> callback) OVERRIDE;
 
- private:
   // FileHandleHolder is used to guarantee that file operations will have a
   // valid FD to operate on, even if they're in a different thread.
   // If instead we just passed the raw FD, the FD could be closed before the
   // file operation has a chance to run. It could interact with an invalid FD,
   // or worse, the FD value could be reused if another file is opened quickly
   // (POSIX is required to provide the lowest available value when opening a
   // file). This could result in strange problems such as writing data to the
   // wrong file.
   //
   // Operations that run on a background thread should hold one of these to
@@ skipping 12 matching lines @@
     PP_FileHandle raw_handle() {
       return raw_handle_;
     }
     static bool IsValid(
         const scoped_refptr<FileIOResource::FileHandleHolder>& handle);
    private:
     friend class base::RefCountedThreadSafe<FileHandleHolder>;
     ~FileHandleHolder();
     PP_FileHandle raw_handle_;
   };
+  scoped_refptr<FileHandleHolder> file_handle() {
+    return file_handle_;
+  }
 
+ private:
   // Class to perform file query operations across multiple threads.
   class QueryOp : public base::RefCountedThreadSafe<QueryOp> {
    public:
     explicit QueryOp(scoped_refptr<FileHandleHolder> file_handle);
 
     // Queries the file. Called on the file thread (non-blocking) or the plugin
     // thread (blocking). This should not be called when we hold the proxy lock.
     int32_t DoWork();
 
     const base::PlatformFileInfo& file_info() const { return file_info_; }
@@ skipping 108 matching lines @@
   bool check_quota_;
   bool called_close_;
 
   DISALLOW_COPY_AND_ASSIGN(FileIOResource);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_FILE_IO_RESOURCE_H_