Fix the build dependency of ProfileSyncService on sync.pb.h

ProfileSyncService requires the file sync/protocol/sync.pb.h to be generated.
However, including browser_sync_browser (which contains ProfileSyncService)
does not guarantee that.

This CL exposes sync/sync.gyp:sync (containing sync.pb.h) as a public
dependency in sync_driver, and sync_driver as a public dependency in
browser_sync_browser, so that any target with the dependency on
browser_sync_browser will also generate sync.pb.h.

BUG=595332

Review URL: https://codereview.chromium.org/1808223002

Cr-Commit-Position: refs/heads/master@{#381712}

components/browser_sync.gypi

@@ -38,6 +38,9 @@
       'include_dirs': [
         '..',
       ],
+      'export_dependent_settings': [
+        'sync_driver',
+      ],
       'sources': [
         # Note: file list duplicated in GN build.
         'browser_sync/browser/profile_sync_components_factory_impl.cc',

components/browser_sync/browser/BUILD.gn

@@ -14,6 +14,10 @@ source_set("browser") {
     "signin_confirmation_helper.h",
   ]
 
+  public_deps = [
+    "//components/sync_driver",
+  ]
+
   deps = [
     "//base",
     "//components/autofill/core/browser",
@@ -31,7 +35,6 @@ source_set("browser") {
     "//components/signin/core/browser",
     "//components/strings",
     "//components/sync_bookmarks",
-    "//components/sync_driver",
     "//components/sync_sessions",
     "//components/syncable_prefs",
     "//components/variations",

components/sync_driver.gypi

@@ -22,6 +22,7 @@
         'version_info',
       ],
       'export_dependent_settings': [
+        '../sync/sync.gyp:sync',
         '../third_party/cacheinvalidation/cacheinvalidation.gyp:cacheinvalidation',
       ],
       'include_dirs': [

components/sync_driver/BUILD.gn

@@ -126,8 +126,10 @@ source_set("sync_driver") {
   ]
 
   public_deps = [
+    "//sync",
     "//third_party/cacheinvalidation",
   ]
+
   deps = [
     "//base",
     "//base/third_party/dynamic_annotations",
@@ -141,7 +143,6 @@ source_set("sync_driver") {
     "//components/version_info",
     "//google_apis",
     "//net",
-    "//sync",
   ]
 
   if (enable_configuration_policy) {