Make VEA test support videos with different coded size and visible size

base/files/memory_mapped_file.h

Index: base/files/memory_mapped_file.h
diff --git a/base/files/memory_mapped_file.h b/base/files/memory_mapped_file.h
index 8a7f045f351a0365d496f37f5824607cacfdc12e..1ab1b459442e3ae7eb0fdb1fed639cff8325a4e2 100644
--- a/base/files/memory_mapped_file.h
+++ b/base/files/memory_mapped_file.h
@@ -48,15 +48,15 @@ class BASE_EXPORT MemoryMappedFile {
   // read only. If this object already points to a valid memory mapped file
   // then this method will fail and return false. If it cannot open the file,
   // the file does not exist, or the memory mapping fails, it will return false.
-  // Later we may want to allow the user to specify access.
   bool Initialize(const FilePath& file_name);
 
-  // As above, but works with an already-opened file. MemoryMappedFile takes
-  // ownership of |file| and closes it when done.
-  bool Initialize(File file);
+  // As above, works with an already-opened file, closes it when done, and

[wuchengli, 2014/09/01 09:19:25]

s/works/but works/?

[Tom Sepez, 2014/09/02 16:57:15]

I'd rather have a InitializeForTesting() method than a |write| parameter; its
too easy down the road for someone to think that it's OK to call this with
write=true in other parts of chrome.

+  // enables write permission when |write| is true.
+  bool Initialize(File file, bool write);
 
-  // As above, but works with a region of an already-opened file.
-  bool Initialize(File file, const Region& region);
+  // As above, but works with a region of an already-opened file and enables
+  // write permission when |write| is true.

[wuchengli, 2014/09/01 09:19:25]

Remove "and enables write permission when |write| is true." That's included by
"As above"

+  bool Initialize(File file, const Region& region, bool write);
 
 #if defined(OS_WIN)
   // Opens an existing file and maps it as an image section. Please refer to
@@ -64,7 +64,7 @@ class BASE_EXPORT MemoryMappedFile {
   bool InitializeAsImageSection(const FilePath& file_name);
 #endif  // OS_WIN
 
-  const uint8* data() const { return data_; }
+  uint8* data() const { return data_; }

[Tom Sepez, 2014/09/02 16:57:15]

You might want, say, mutable_data_for_testing() to return the non-const version.

   size_t length() const { return length_; }
 
   // Is file_ a valid file handle that points to an open, memory mapped file?
@@ -85,7 +85,8 @@ class BASE_EXPORT MemoryMappedFile {
 
   // Map the file to memory, set data_ to that memory address. Return true on
   // success, false on any kind of failure. This is a helper for Initialize().
-  bool MapFileRegionToMemory(const Region& region);
+  // - |write| is used to enable write permission of mmap.
+  bool MapFileRegionToMemory(const Region& region, bool write);
 
   // Closes all open handles.
   void CloseHandles();