Safebrowsing: Fix comments pointing to internal URL for API docs.

BUG=

Review URL: https://codereview.chromium.org/588803002

Cr-Commit-Position: refs/heads/master@{#296041}

chrome/browser/safe_browsing/chunk.proto

@@ -9,7 +9,7 @@ option optimize_for = LITE_RUNTIME;
 package safe_browsing;
 
 // Everything below this comment was copied from the page
-// <https://devsite.googleplex.com/safe-browsing/developers_guide_v3> ,
+// <https://developers.google.com/safe-browsing/developers_guide_v3>,
 // section "HTTP Response for Data" under "Response Body".
 
 // Chunk data encoding format for the shavar-proto list format.

chrome/browser/safe_browsing/protocol_parser.h

@@ -6,7 +6,7 @@
 #define CHROME_BROWSER_SAFE_BROWSING_PROTOCOL_PARSER_H_
 
 // Parsers and formatters for SafeBrowsing v3.0 protocol:
-// https://devsite.googleplex.com/safe-browsing/developers_guide_v3
+// https://developers.google.com/safe-browsing/developers_guide_v3
 //
 // The quoted references are with respect to that document.