Refactor safe-browsing build-config definitions.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index d4018b5182f55db594862cd00743c0b51860f36c..fe7f048cc295899a17336f1347a339b3604d44ea 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -2852,6 +2852,25 @@
       ['video_hole==1', {
         'defines': ['VIDEO_HOLE=1'],
       }],
+
+      # SAFE_BROWSING_SERVICE - browser manages a safe-browsing service.
+      # SAFE_BROWSING_DATABASE - service manages a local database.
+      # SAFE_BROWSING_CSD - enable client-side phishing detection.
+      ['safe_browsing==1', {
+        'defines': [
+          'FULL_SAFE_BROWSING',
+          'SAFE_BROWSING_CSD',
+          'SAFE_BROWSING_DATABASE',
+          'SAFE_BROWSING_SERVICE',
+        ],
+      }],
+      # TODO(shess): I believe this case is no longer in use.
+      ['safe_browsing==2', {
+        'defines': [
+          'MOBILE_SAFE_BROWSING',
+          'SAFE_BROWSING_SERVICE',
+        ],
+      }],
     ],  # conditions for 'target_defaults'
     'target_conditions': [
       ['<(use_openssl)==1', {