Add more components unittests to the GN build.

components/data_reduction_proxy/core/common/BUILD.gn

Index: components/data_reduction_proxy/core/common/BUILD.gn
diff --git a/components/data_reduction_proxy/core/common/BUILD.gn b/components/data_reduction_proxy/core/common/BUILD.gn
index b11ca2e5ef2db5d1a147d284b02cd2f9a301e9c9..0a1463d23190ccf528600b694070e36d4347beaf 100644
--- a/components/data_reduction_proxy/core/common/BUILD.gn
+++ b/components/data_reduction_proxy/core/common/BUILD.gn
@@ -18,21 +18,29 @@ static_library("common") {
     "data_reduction_proxy_switches.h",
   ]
 
-  deps = [
+  public_deps = [
     ":version_header",
+  ]
+  deps = [
     "//base",
+    "//net",
+    "//url",
   ]
 }
 
-static_library("test_support") {
+source_set("test_support") {
   testonly = true
   sources = [
+    "data_reduction_proxy_headers_test_utils.cc",
+    "data_reduction_proxy_headers_test_utils.h",
     "data_reduction_proxy_params_test_utils.cc",
     "data_reduction_proxy_params_test_utils.h",
   ]
 
-  deps = [
+  public_deps = [
     ":common",
+  ]
+  deps = [
     "//base",
     "//net",
     "//net:test_support",
@@ -51,6 +59,10 @@ source_set("unit_tests") {
 
   deps = [
     ":common",
+    ":test_support",
+    "//base",
+    "//base/test:test_support",
+    "//net:test_support",
     "//testing/gtest",
   ]
 }