gn BUILD fixes for disabling enable_extensions and use_ash feature flags.

chrome/test/BUILD.gn

Index: chrome/test/BUILD.gn
diff --git a/chrome/test/BUILD.gn b/chrome/test/BUILD.gn
index 46e52b45d482d252f20214e9641df4fd9516da27..4ff70faea298add7196a48551600a9d403bf2262 100644
--- a/chrome/test/BUILD.gn
+++ b/chrome/test/BUILD.gn
@@ -365,7 +365,9 @@ if (!is_android) {
     # TODO(rockot) bug 505926: The chrome_extensions_interactive_uitests target
     # should be deleted and this line removed. See the
     # chrome_extensions_interactive_uitests target for more.
-    deps += [ "//extensions:chrome_extensions_interactive_uitests" ]
+    if (enable_extensions) {
+      deps += [ "//extensions:chrome_extensions_interactive_uitests" ]
+    }
 
     # Runtime dependencies
     data_deps = [
@@ -896,7 +898,6 @@ if (!is_android) {
       "//chrome:strings",
       "//chrome/browser",
       "//chrome/browser/resources:extension_resource_demo",
-      "//chrome/common/extensions/api",
       "//chrome/renderer",
       "//components/autofill/content/browser:risk_proto",
       "//components/autofill/content/browser/wallet:test_support",
@@ -916,7 +917,6 @@ if (!is_android) {
       "//crypto:test_support",
       "//device/bluetooth:mocks",
       "//device/serial:test_support",
-      "//extensions/common/api",
       "//google_apis:test_support",
       "//media",
       "//media/base:test_support",
@@ -946,11 +946,19 @@ if (!is_android) {
       "//ui/web_dialogs:test_support",
       "//v8",
     ]
+    if (enable_extensions) {
+      deps += [
+        "//chrome/common/extensions/api",
+        "//extensions/common/api",
+      ]
+    }
 
     # TODO(rockot) bug 505926: The chrome_extensions_browsertests target should
     # be deleted and this line removed. See the chrome_extensions_browsertests
     # target for more.
-    deps += [ "//extensions:chrome_extensions_browsertests" ]
+    if (enable_extensions) {
+      deps += [ "//extensions:chrome_extensions_browsertests" ]
+    }
 
     # Runtime dependencies
     data_deps = [