Added is_jailbroken boolean flag to OS protobuf.

components/metrics/proto/system_profile.proto

Index: components/metrics/proto/system_profile.proto
diff --git a/components/metrics/proto/system_profile.proto b/components/metrics/proto/system_profile.proto
index c128a350a8915ea3898ded280f82db7996ad69c6..456b0a4bf397ba2fe4ad2503e06c05cd864ccb8d 100644
--- a/components/metrics/proto/system_profile.proto
+++ b/components/metrics/proto/system_profile.proto
@@ -80,6 +80,12 @@ message SystemProfileProto {
 
     // The fingerprint of the build.  This field is used only on Android.
     optional string fingerprint = 3;
+
+    // Whether the version of iOS appears to be "jailbroken". This field is
+    // used only on iOS. Chrome for iOS detects whether device contains a
+    // DynamicLibraries/ directory. It's a necessary but insufficient indicator
+    // of whether the operating system has been jailbroken.
+    optional bool is_jailbroken = 4;
   }
   optional OS os = 5;