Clean up gyp settings for libjpeg

third_party/libjpeg/libjpeg.gyp

Index: third_party/libjpeg/libjpeg.gyp
diff --git a/third_party/libjpeg/libjpeg.gyp b/third_party/libjpeg/libjpeg.gyp
index 12cc882310cc5fbf9f3b2718854ef15bca606579..8f0dac82645fb45ed10a92656fc05825f4da470f 100644
--- a/third_party/libjpeg/libjpeg.gyp
+++ b/third_party/libjpeg/libjpeg.gyp
@@ -3,16 +3,8 @@
 # found in the LICENSE file.
 
 {
-  'variables': {
-    'conditions': [
-      [ 'os_posix == 1 and OS != "mac"', {
-        # Link to system .so since we already use it due to GTK.
-        'use_system_libjpeg%': 1,
-      }, {  # os_posix != 1 or OS == "mac"
-        'use_system_libjpeg%': 0,
-      }],
-    ],
-  },
+  # This file handles building both with our local libjpeg and with the system
+  # libjpeg.
   'conditions': [
     ['use_system_libjpeg==0', {
       'targets': [
@@ -94,6 +86,13 @@
             'defines': [
               'USE_SYSTEM_LIBJPEG',
             ],
+            'conditions': [
+              ['os_bsd==1', {
+                'include_dirs': [
+                  '/usr/local/include',
+                ],
+              }],
+            ],
           },
           'link_settings': {
             'libraries': [