mac: Remove POSIX shared memory.

base/memory/shared_memory.h

Index: base/memory/shared_memory.h
diff --git a/base/memory/shared_memory.h b/base/memory/shared_memory.h
index 13238aabacb1fb4f6924f4bf9b596e9517952861..b7e5a050603d52fce8e41b513c13454b2e5c6be6 100644
--- a/base/memory/shared_memory.h
+++ b/base/memory/shared_memory.h
@@ -32,10 +32,7 @@ class FilePath;
 struct BASE_EXPORT SharedMemoryCreateOptions {
   SharedMemoryCreateOptions();
 
-#if defined(OS_MACOSX) && !defined(OS_IOS)
-  // The type of OS primitive that should back the SharedMemory object.
-  SharedMemoryHandle::Type type;
-#else
+#if !(defined(OS_MACOSX) && !defined(OS_IOS))

[Avi (use Gerrit), 2016/04/09 00:13:40]

OMG

Does iOS use this? Can we just say #if !defined(OS_MACOSX)? Or do we leave this,
and when we remove the two deprecated fields guarded by the #if, the problem
goes away?

[erikchen, 2016/04/09 00:20:50]

iOS still uses the POSIX implementation for shared memory, as well as all the
POSIX shared memory tests, which require these fields.

   // DEPRECATED (crbug.com/345734):
   // If NULL, the object is anonymous.  This pointer is owned by the caller
   // and must live through the call to Create().
@@ -47,7 +44,7 @@ struct BASE_EXPORT SharedMemoryCreateOptions {
   // shared memory must not exist.  This flag is meaningless unless
   // name_deprecated is non-NULL.
   bool open_existing_deprecated;
-#endif  // defined(OS_MACOSX) && !defined(OS_IOS)
+#endif  // !(defined(OS_MACOSX) && !defined(OS_IOS))
 
   // Size of the shared memory object to be created.
   // When opening an existing object, this has no effect.
@@ -102,7 +99,7 @@ class BASE_EXPORT SharedMemory {
   // The caller is responsible for destroying the duplicated OS primitive.
   static SharedMemoryHandle DuplicateHandle(const SharedMemoryHandle& handle);
 
-#if defined(OS_POSIX)
+#if defined(OS_POSIX) && !(defined(OS_MACOSX) && !defined(OS_IOS))
   // This method requires that the SharedMemoryHandle is backed by a POSIX fd.
   static int GetFdFromSharedMemoryHandle(const SharedMemoryHandle& handle);
 #endif
@@ -123,16 +120,6 @@ class BASE_EXPORT SharedMemory {
   // Returns true on success and false on failure.
   bool CreateAndMapAnonymous(size_t size);
 
-#if defined(OS_MACOSX) && !defined(OS_IOS)
-  // These two methods are analogs of CreateAndMapAnonymous and CreateAnonymous
-  // that force the underlying OS primitive to be a POSIX fd. Do not add new
-  // uses of these methods unless absolutely necessary, since constructing a
-  // fd-backed SharedMemory object frequently takes 100ms+.
-  // http://crbug.com/466437.
-  bool CreateAndMapAnonymousPosix(size_t size);
-  bool CreateAnonymousPosix(size_t size);
-#endif  // defined(OS_MACOSX) && !defined(OS_IOS)
-
   // Creates an anonymous shared memory segment of size size.
   // Returns true on success and false on failure.
   bool CreateAnonymous(size_t size) {
@@ -257,12 +244,11 @@ class BASE_EXPORT SharedMemory {
   }
 
  private:
-#if defined(OS_POSIX) && !defined(OS_NACL) && !defined(OS_ANDROID)
+#if defined(OS_POSIX) && !defined(OS_NACL) && !defined(OS_ANDROID) && \
+    !(defined(OS_MACOSX) && !defined(OS_IOS))
   bool PrepareMapFile(ScopedFILE fp, ScopedFD readonly);
-#if !(defined(OS_MACOSX) && !defined(OS_IOS))
   bool FilePathForMemoryName(const std::string& mem_name, FilePath* path);
 #endif
-#endif  // defined(OS_POSIX) && !defined(OS_NACL) && !defined(OS_ANDROID)
   enum ShareMode {
     SHARE_READONLY,
     SHARE_CURRENT_MODE,
@@ -282,10 +268,6 @@ class BASE_EXPORT SharedMemory {
   // The OS primitive that backs the shared memory region.
   SharedMemoryHandle shm_;
 
-  // The mechanism by which the memory is mapped. Only valid if |memory_| is not
-  // |nullptr|.
-  SharedMemoryHandle::Type mapped_memory_mechanism_;
-
   int readonly_mapped_file_;
 #elif defined(OS_POSIX)
   int                mapped_file_;