skia: Fix command buffer support on the mac

gyp/common_conditions.gypi

Index: gyp/common_conditions.gypi
diff --git a/gyp/common_conditions.gypi b/gyp/common_conditions.gypi
index bbe716b9de0c3c94267449e606eb73aa21725056..02113c3f8a531f4624ab0ef745b4bb9a7a2761dc 100644
--- a/gyp/common_conditions.gypi
+++ b/gyp/common_conditions.gypi
@@ -617,12 +617,18 @@
       ],
     }],
 
-    [ 'skia_command_buffer', {
+    [ 'skia_command_buffer and skia_os == "linux"', {
       'ldflags': [
           '-Wl,-rpath,\$$ORIGIN/lib',
       ],
     }],
 
+    [ 'skia_command_buffer and skia_os == "mac"', {
+      'xcode_settings': {
+          'LD_RUNPATH_SEARCH_PATHS': ['@executable_path/.'],
+      },
+    }],
+
   ], # end 'conditions'
   # The Xcode SYMROOT must be at the root. See build/common.gypi in chromium for more details
   'xcode_settings': {