Fix the missing "data_store.pb.h" error when building extensions gn target on...

Fix the missing "data_store.pb.h" error when building extensions gn target on a clean output directory.

data_reduction_proxy_api.cc includes data_store.pb.h directly and indirectly (via data_reduction_proxy_compression_stats.h). This CL adds //components/data_reduction_proxy/proto:data_reduction_proxy_proto to the dependencies of extensions to solve this problem.

BUG=560321

Review URL: https://codereview.chromium.org/1460313004

Cr-Commit-Position: refs/heads/master@{#361149}

chrome/browser/extensions/BUILD.gn

@@ -44,6 +44,7 @@ source_set("extensions") {
     "//chrome/common/safe_browsing:proto",
     "//chrome/installer/util",
     "//components/copresence",
+    "//components/data_reduction_proxy/proto:data_reduction_proxy_proto",
     "//components/dom_distiller/core",
     "//components/onc",
     "//components/proximity_auth",