Revert of Don't set -fvisibility=hidden for iOS Debug in GYP.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index a3e2bee6bb8955f7daf1c23208e5a4cd1d9c90b1..d829ae4141a84a3edfc57772c03e009b8b86bfcc 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -5081,6 +5081,7 @@
           # GCC_INLINES_ARE_PRIVATE_EXTERN maps to -fvisibility-inlines-hidden
           'GCC_INLINES_ARE_PRIVATE_EXTERN': 'YES',
           'GCC_OBJC_CALL_CXX_CDTORS': 'YES',        # -fobjc-call-cxx-cdtors
+          'GCC_SYMBOLS_PRIVATE_EXTERN': 'YES',      # -fvisibility=hidden
           'GCC_THREADSAFE_STATICS': 'NO',           # -fno-threadsafe-statics
           'GCC_TREAT_WARNINGS_AS_ERRORS': 'YES',    # -Werror
           'GCC_VERSION': '4.2',
@@ -5142,34 +5143,15 @@
                 '-fcolor-diagnostics',
               ],
             }],
-            ['OS=="ios"', {
-              'configurations': {
-                'Debug': {
-                  # XCTests inject a dynamic library into the application. If
-                  # fvisibility is set to hidden, then some symbols needed by
-                  # XCTests are not available. Disable this setting for
-                  # Debug configuration.
-                  'GCC_SYMBOLS_PRIVATE_EXTERN': 'NO',
-                },
-                'Release': {
-                  'GCC_SYMBOLS_PRIVATE_EXTERN': 'YES',    # -fvisibility=hidden
-                },
-              },
-              'conditions': [
-                ['target_subarch!="arm32" and "<(GENERATOR)"=="xcode"', {
-                  'OTHER_CFLAGS': [
-                    # TODO(ios): when building Chrome for iOS on 64-bit
-                    # platform with Xcode, the -Wshorted-64-to-32 warning is
-                    # automatically enabled. This causes failures when
-                    # compiling protobuf code, so disable the warning.
-                    # http://crbug.com/359107
-                    '-Wno-shorten-64-to-32',
-                  ],
-                }],
+            ['OS=="ios" and target_subarch!="arm32" and \
+              "<(GENERATOR)"=="xcode"', {
+              'OTHER_CFLAGS': [
+                # TODO(ios): when building Chrome for iOS on 64-bit platform
+                # with Xcode, the -Wshorted-64-to-32 warning is automatically
+                # enabled. This cause failures when compiling protobuf code,
+                # so disable the warning. http://crbug.com/359107
+                '-Wno-shorten-64-to-32',
               ],
-            }],
-            ['OS=="mac"', {
-              'GCC_SYMBOLS_PRIVATE_EXTERN': 'YES',    # -fvisibility=hidden
             }],
           ],
         },