ShapeDetection: add support for Text Detection in Mac

base/mac/sdk_forward_declarations.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.
 
 // This file contains forward declarations for items in later SDKs than the
 // default one with which Chromium is built (currently 10.10).
 // If you call any function from this header, be sure to check at runtime for
 // respondsToSelector: before calling these functions (else your code will crash
 // on older OS X versions that chrome still supports).
 
@@ skipping 145 matching lines @@
 @interface NSEvent (Yosemite_3_SDK)
 @property(readonly) NSInteger stage;
 @end
 
 @interface NSView (Yosemite_3_SDK)
 - (void)setPressureConfiguration:(NSPressureConfiguration*)aConfiguration;
 @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.
 #if !defined(MAC_OS_X_VERSION_10_11) || \
     MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_11
 
 @class NSLayoutDimension;
 @class NSLayoutXAxisAnchor;
 @class NSLayoutYAxisAnchor;
 
 @interface NSObject (ElCapitanSDK)
@@ skipping 55 matching lines @@
 
 // ----------------------------------------------------------------------------
 // The symbol for kCWSSIDDidChangeNotification is available in the
 // CoreWLAN.framework for OSX versions 10.6 through 10.10. The symbol is not
 // declared in the OSX 10.9+ SDK, so when compiling against an OSX 10.9+ SDK,
 // declare the symbol.
 // ----------------------------------------------------------------------------
 BASE_EXPORT extern "C" NSString* const kCWSSIDDidChangeNotification;
 
 #endif  // BASE_MAC_SDK_FORWARD_DECLARATIONS_H_