Fix NotBlockedExternalUserProviders

Add Windows specific code to test registry provider blocked by the policy.

Bug: 1019160
Change-Id: I5ae7c383028b2a6a51075d76b60ae01dc507034c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1893572Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Commit-Queue: Dominique Fauteux-Chapleau <domfc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#713555}

chrome/browser/extensions/external_provider_impl_unittest.cc

@@ -48,6 +48,11 @@
 #include "components/user_manager/scoped_user_manager.h"
 #endif
 
+#if defined(OS_WIN)
+#include "base/test/test_reg_util_win.h"
+#include "base/win/registry.h"
+#endif
+
 namespace extensions {
 
 namespace {
@@ -59,6 +64,13 @@ const char kAppPath[] = "/app.crx";
 const char kExternalAppId[] = "kekdneafjmhmndejhmbcadfiiofngffo";
 #endif
 
+#if defined(OS_WIN)
+const char kExternalAppCrxPath[] =
+    "external\\kekdneafjmhmndejhmbcadfiiofngffo.crx";
+const wchar_t kExternalAppRegistryKey[] =
+    L"Software\\Google\\Chrome\\Extensions\\kekdneafjmhmndejhmbcadfiiofngffo";
+#endif
+
 class ExternalProviderImplTest : public ExtensionServiceTestBase {
  public:
   ExternalProviderImplTest() {}
@@ -92,8 +104,25 @@ class ExternalProviderImplTest : public ExtensionServiceTestBase {
   }
 
   void OverrideExternalExtensionsPath() {
+    // Windows doesn't use the provider that installs the |kExternalAppId|
+    // extension implicitly, so to test that the blocking policy works on
+    // Windows it is installed through a Windows-specific registry provider.
+#if defined(OS_WIN)
+    EXPECT_NO_FATAL_FAILURE(
+        registry_override_manager_.OverrideRegistry(HKEY_CURRENT_USER));
+    EXPECT_EQ(ERROR_SUCCESS,
+              external_extension_key_.Create(
+                  HKEY_CURRENT_USER, kExternalAppRegistryKey, KEY_ALL_ACCESS));
+    EXPECT_EQ(ERROR_SUCCESS,
+              external_extension_key_.WriteValue(
+                  L"path",
+                  data_dir().AppendASCII(kExternalAppCrxPath).value().c_str()));
+    EXPECT_EQ(ERROR_SUCCESS,
+              external_extension_key_.WriteValue(L"version", L"1"));
+#else
     external_externsions_overrides_.reset(new base::ScopedPathOverride(
         chrome::DIR_EXTERNAL_EXTENSIONS, data_dir().AppendASCII("external")));
+#endif
   }
 
   void SetExternalExtensionsBlockedByPolicy(const bool block_external) {
@@ -174,6 +203,12 @@ class ExternalProviderImplTest : public ExtensionServiceTestBase {
   chromeos::system::ScopedFakeStatisticsProvider fake_statistics_provider_;
 #endif
 
+#if defined(OS_WIN)
+  // Registry key pointing to the external extension for Windows.
+  base::win::RegKey external_extension_key_;
+  registry_util::RegistryOverrideManager registry_override_manager_;
+#endif
+
   DISALLOW_COPY_AND_ASSIGN(ExternalProviderImplTest);
 };