First pass on intents options UI.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index ee0334ba9194fca62a0445ff6370e4aee05c8b08..96cb522306a298d5b3784c208f20a3a3d90e3caa 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -314,6 +314,7 @@
     'asan%': '<(asan)',
     'enable_register_protocol_handler%': '<(enable_register_protocol_handler)',
     'enable_smooth_scrolling%': '<(enable_smooth_scrolling)',
+    'enable_web_intents%': '<(enable_web_intents)',
     # Whether to build for Wayland display server
     'use_wayland%': 0,
 
@@ -697,6 +698,10 @@
         'grit_defines': ['-D', 'enable_register_protocol_handler'],
       }],
 
+      ['enable_web_intents==1', {
+        'grit_defines': ['-D', 'enable_web_intents'],
+      }],
+
       ['asan==1', {
         'clang%': 1,
       }],
@@ -908,6 +913,11 @@
           'ENABLE_REGISTER_PROTOCOL_HANDLER=1',
         ],
       }],
+      ['enable_web_intents==1', {
+        'defines': [
+          'ENABLE_INTENTS=1',
+        ],
+      }],
     ],  # conditions for 'target_defaults'
     'target_conditions': [
       ['chromium_code==0', {