Revert of ShapeDetection: add support for Text Detection in Mac

base/mac/sdk_forward_declarations.h

Index: base/mac/sdk_forward_declarations.h
diff --git a/base/mac/sdk_forward_declarations.h b/base/mac/sdk_forward_declarations.h
index 5416c6f94658283c5de4da33c0d83790c7425c7a..7ea7829d9afeb38f0fa224317093c04c88012f02 100644
--- a/base/mac/sdk_forward_declarations.h
+++ b/base/mac/sdk_forward_declarations.h
@@ -162,18 +162,6 @@
 @end
 
 #endif  // MAC_OS_X_VERSION_10_10
-
-// ----------------------------------------------------------------------------
-// Define NSStrings only available in newer versions of the OSX SDK to force
-// them to be statically linked.
-// ----------------------------------------------------------------------------
-
-extern "C" {
-#if !defined(MAC_OS_X_VERSION_10_11) || \
-    MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_11
-BASE_EXPORT extern NSString* const CIDetectorTypeText;
-#endif  // MAC_OS_X_VERSION_10_11
-}  // extern "C"
 
 // Once Chrome no longer supports OSX 10.10, everything within this
 // preprocessor block can be removed.