Include sync.pb.h in sync_data.h.

chrome/chrome.gyp

Index: chrome/chrome.gyp
diff --git a/chrome/chrome.gyp b/chrome/chrome.gyp
index f4c319966dda7e1cce94ffdfa04dfaa25f3416dd..3e80793e27dbb59e3a8e91da73a6eb579f6fd532 100644
--- a/chrome/chrome.gyp
+++ b/chrome/chrome.gyp
@@ -143,6 +143,11 @@
             '../net/net.gyp:http_server',
             '../net/net.gyp:net',
             '../skia/skia.gyp:skia',
+            # Declaring a dependency on sync because debugger depends on
+            # browser, which depends on sync. We cannot simply declare a

[Nico, 2014/03/07 19:13:00]

In what way does debugger depend on browser? Does it include a header from
browser? Since a real dependency would be a cycle as you note, could this wrong
include be fixed instead?

[maniscalco, 2014/03/07 23:44:37]

Good question.  I've removed/replaced some #includes and used forward
declarations where possible.  This dependency is no longer needed.

+            # dependency on browser because that would create a cycle (browser
+            # already depends on debugger).
+            '../sync/sync.gyp:sync',
             '../third_party/icu/icu.gyp:icui18n',
             '../third_party/icu/icu.gyp:icuuc',
             '../third_party/leveldatabase/leveldatabase.gyp:leveldatabase',