Move ExtensionCache to //extensions

This moves the ExtensionCache interface out to extensions and
delegates instance provisioning out to ExtensionsBrowserClient
implementations.

BUG=398671

Review URL: https://codereview.chromium.org/612423003

Cr-Commit-Position: refs/heads/master@{#299192}

chrome/browser/extensions/chrome_extensions_browser_client.cc

@@ -40,7 +40,10 @@
 #include "extensions/browser/url_request_util.h"
 
 #if defined(OS_CHROMEOS)
+#include "chrome/browser/extensions/updater/extension_cache_impl.h"
 #include "chromeos/chromeos_switches.h"
+#else
+#include "extensions/browser/updater/null_extension_cache.h"
 #endif
 
 namespace extensions {
@@ -51,6 +54,12 @@ ChromeExtensionsBrowserClient::ChromeExtensionsBrowserClient() {
   // Only set if it hasn't already been set (e.g. by a test).
   if (GetCurrentChannel() == GetDefaultChannel())
     SetCurrentChannel(chrome::VersionInfo::GetChannel());
+
+#if defined(OS_CHROMEOS)
+  extension_cache_.reset(new ExtensionCacheImpl());
+#else
+  extension_cache_.reset(new NullExtensionCache());
+#endif
 }
 
 ChromeExtensionsBrowserClient::~ChromeExtensionsBrowserClient() {}
@@ -242,6 +251,13 @@ void ChromeExtensionsBrowserClient::RegisterExtensionFunctions(
   extensions::api::GeneratedFunctionRegistry::RegisterAll(registry);
 }
 
+scoped_ptr<extensions::RuntimeAPIDelegate>
+ChromeExtensionsBrowserClient::CreateRuntimeAPIDelegate(
+    content::BrowserContext* context) const {
+  return scoped_ptr<extensions::RuntimeAPIDelegate>(
+      new ChromeRuntimeAPIDelegate(context));
+}
+
 ComponentExtensionResourceManager*
 ChromeExtensionsBrowserClient::GetComponentExtensionResourceManager() {
   if (!resource_manager_)
@@ -260,11 +276,8 @@ net::NetLog* ChromeExtensionsBrowserClient::GetNetLog() {
   return g_browser_process->net_log();
 }
 
-scoped_ptr<extensions::RuntimeAPIDelegate>
-ChromeExtensionsBrowserClient::CreateRuntimeAPIDelegate(
-    content::BrowserContext* context) const {
-  return scoped_ptr<extensions::RuntimeAPIDelegate>(
-      new ChromeRuntimeAPIDelegate(context));
+ExtensionCache* ChromeExtensionsBrowserClient::GetExtensionCache() {
+  return extension_cache_.get();
 }
 
 }  // namespace extensions

chrome/browser/extensions/chrome_extensions_browser_client.h

@@ -96,6 +96,7 @@ class ChromeExtensionsBrowserClient : public ExtensionsBrowserClient {
       const std::string& event_name,
       scoped_ptr<base::ListValue> args) override;
   virtual net::NetLog* GetNetLog() override;
+  virtual ExtensionCache* GetExtensionCache() override;
 
  private:
   friend struct base::DefaultLazyInstanceTraits<ChromeExtensionsBrowserClient>;
@@ -111,6 +112,8 @@ class ChromeExtensionsBrowserClient : public ExtensionsBrowserClient {
 
   scoped_ptr<ChromeComponentExtensionResourceManager> resource_manager_;
 
+  scoped_ptr<ExtensionCache> extension_cache_;
+
   DISALLOW_COPY_AND_ASSIGN(ChromeExtensionsBrowserClient);
 };
 

chrome/browser/extensions/extension_browsertest.cc

@@ -24,6 +24,7 @@
 #include "chrome/browser/extensions/extension_util.h"
 #include "chrome/browser/extensions/unpacked_installer.h"
 #include "chrome/browser/extensions/updater/extension_cache_fake.h"
+#include "chrome/browser/extensions/updater/extension_updater.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/ui/browser.h"
@@ -132,6 +133,10 @@ void ExtensionBrowserTest::SetUpCommandLine(CommandLine* command_line) {
 void ExtensionBrowserTest::SetUpOnMainThread() {
   InProcessBrowserTest::SetUpOnMainThread();
   observer_.reset(new ExtensionTestNotificationObserver(browser()));
+  if (extension_service()->updater()) {
+    extension_service()->updater()->SetExtensionCacheForTesting(
+        test_extension_cache_.get());
+  }
 }
 
 const Extension* ExtensionBrowserTest::LoadExtension(

chrome/browser/extensions/extension_disabled_ui_browsertest.cc

@@ -41,6 +41,7 @@ class ExtensionDisabledGlobalErrorTest : public ExtensionBrowserTest {
   }
 
   virtual void SetUpOnMainThread() override {
+    ExtensionBrowserTest::SetUpOnMainThread();
     EXPECT_TRUE(scoped_temp_dir_.CreateUniqueTempDir());
     service_ = extensions::ExtensionSystem::Get(
         browser()->profile())->extension_service();

chrome/browser/extensions/extension_service.cc

@@ -42,7 +42,6 @@
 #include "chrome/browser/extensions/shared_module_service.h"
 #include "chrome/browser/extensions/unpacked_installer.h"
 #include "chrome/browser/extensions/updater/chrome_extension_downloader_factory.h"
-#include "chrome/browser/extensions/updater/extension_cache.h"
 #include "chrome/browser/extensions/updater/extension_downloader.h"
 #include "chrome/browser/extensions/updater/extension_updater.h"
 #include "chrome/browser/google/google_brand.h"
@@ -68,10 +67,12 @@
 #include "extensions/browser/extension_prefs.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/browser/extension_system.h"
+#include "extensions/browser/extensions_browser_client.h"
 #include "extensions/browser/install_flag.h"
 #include "extensions/browser/runtime_data.h"
 #include "extensions/browser/uninstall_reason.h"
 #include "extensions/browser/update_observer.h"
+#include "extensions/browser/updater/extension_cache.h"
 #include "extensions/common/extension_messages.h"
 #include "extensions/common/extension_urls.h"
 #include "extensions/common/feature_switch.h"
@@ -185,7 +186,8 @@ bool ExtensionService::OnExternalExtensionUpdateUrlFound(
 
   if (Manifest::IsExternalLocation(location)) {
     // All extensions that are not user specific can be cached.
-    extensions::ExtensionCache::GetInstance()->AllowCaching(id);
+    extensions::ExtensionsBrowserClient::Get()->GetExtensionCache()
+        ->AllowCaching(id);
   }
 
   const Extension* extension = GetExtensionById(id, true);
@@ -307,7 +309,7 @@ ExtensionService::ExtensionService(Profile* profile,
         profile->GetPrefs(),
         profile,
         update_frequency,
-        extensions::ExtensionCache::GetInstance(),
+        extensions::ExtensionsBrowserClient::Get()->GetExtensionCache(),
         base::Bind(ChromeExtensionDownloaderFactory::CreateForProfile,
                    profile)));
   }

chrome/browser/extensions/external_provider_impl_unittest.cc

@@ -16,6 +16,7 @@
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_service_test_base.h"
 #include "chrome/browser/extensions/updater/extension_cache_fake.h"
+#include "chrome/browser/extensions/updater/extension_updater.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/extension_constants.h"
@@ -62,6 +63,9 @@ class ExternalProviderImplTest : public ExtensionServiceTestBase {
 #endif
     InitializeExtensionServiceWithUpdater();
 
+    service()->updater()->SetExtensionCacheForTesting(
+        test_extension_cache_.get());
+
     // Don't install default apps. Some of the default apps are downloaded from
     // the webstore, ignoring the url we pass to kAppsGalleryUpdateURL, which
     // would cause the external updates to never finish install.

chrome/browser/extensions/updater/extension_cache.cc

-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "chrome/browser/extensions/updater/extension_cache.h"
-
-#include "base/memory/singleton.h"
-
-#if defined(OS_CHROMEOS)
-#include "chrome/browser/extensions/updater/extension_cache_impl.h"
-#endif  // OS_CHROMEOS
-
-namespace extensions {
-namespace {
-
-#if !defined(OS_CHROMEOS)
-
-// Implementation of ExtensionCache that doesn't cache anything.
-// Real cache is used only on Chrome OS other OSes use this null implementation.
-class ExtensionCacheNullImpl : public ExtensionCache {
- public:
-  static ExtensionCacheNullImpl* GetInstance() {
-    return Singleton<ExtensionCacheNullImpl>::get();
-  }
-
-  // Implementation of ExtensionCache.
-  virtual void Start(const base::Closure& callback) override {
-    callback.Run();
-  }
-
-  virtual void Shutdown(const base::Closure& callback) override {
-    callback.Run();
-  }
-
-  virtual void AllowCaching(const std::string& id) override {
-  }
-
-  virtual bool GetExtension(const std::string& id,
-                            base::FilePath* file_path,
-                            std::string* version) override {
-    return false;
-  }
-
-  virtual void PutExtension(const std::string& id,
-                            const base::FilePath& file_path,
-                            const std::string& version,
-                            const PutExtensionCallback& callback) override {
-    callback.Run(file_path, true);
-  }
-
- private:
-  friend struct DefaultSingletonTraits<ExtensionCacheNullImpl>;
-
-  ExtensionCacheNullImpl() {}
-  virtual ~ExtensionCacheNullImpl() {}
-};
-
-#endif  // !OS_CHROMEOS
-
-static ExtensionCache* g_extension_cache_override = NULL;
-
-}  // namespace
-
-// static
-ExtensionCache* ExtensionCache::GetInstance() {
-  if (g_extension_cache_override) {
-    return g_extension_cache_override;
-  } else {
-#if defined(OS_CHROMEOS)
-    return ExtensionCacheImpl::GetInstance();
-#else
-    return ExtensionCacheNullImpl::GetInstance();
-#endif
-  }
-}
-
-// static
-ExtensionCache* ExtensionCache::SetForTesting(ExtensionCache* cache) {
-  ExtensionCache* temp = g_extension_cache_override;
-  g_extension_cache_override = cache;
-  return temp;
-}
-
-}  // namespace extensions

chrome/browser/extensions/updater/extension_cache_fake.cc

@@ -11,11 +11,9 @@
 namespace extensions {
 
 ExtensionCacheFake::ExtensionCacheFake() {
-  ExtensionCache::SetForTesting(this);
 }
 
 ExtensionCacheFake::~ExtensionCacheFake() {
-  ExtensionCache::SetForTesting(NULL);
 }
 
 void ExtensionCacheFake::Start(const base::Closure& callback) {

chrome/browser/extensions/updater/extension_cache_fake.h

@@ -9,7 +9,7 @@
 #include <set>
 #include <string>
 
-#include "chrome/browser/extensions/updater/extension_cache.h"
+#include "extensions/browser/updater/extension_cache.h"
 
 namespace extensions {
 

chrome/browser/extensions/updater/extension_cache_impl.cc

@@ -35,11 +35,6 @@ const int kMaxCacheAgeDays = 30;
 
 }  // namespace
 
-// static
-ExtensionCacheImpl* ExtensionCacheImpl::GetInstance() {
-  return Singleton<ExtensionCacheImpl>::get();
-}
-
 ExtensionCacheImpl::ExtensionCacheImpl()
   : cache_(new LocalExtensionCache(base::FilePath(kLocalCacheDir),
         kMaxCacheSize,

chrome/browser/extensions/updater/extension_cache_impl.h

@@ -13,9 +13,9 @@
 #include "base/files/file_path.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
-#include "chrome/browser/extensions/updater/extension_cache.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
+#include "extensions/browser/updater/extension_cache.h"
 
 template <typename T> struct DefaultSingletonTraits;
 
@@ -28,7 +28,8 @@ class LocalExtensionCache;
 class ExtensionCacheImpl : public ExtensionCache,
                            public content::NotificationObserver {
  public:
-  static ExtensionCacheImpl* GetInstance();
+  ExtensionCacheImpl();
+  virtual ~ExtensionCacheImpl();
 
   // Implementation of ExtensionCache.
   virtual void Start(const base::Closure& callback) override;
@@ -48,11 +49,6 @@ class ExtensionCacheImpl : public ExtensionCache,
                        const content::NotificationDetails& details) override;
 
  private:
-  friend struct DefaultSingletonTraits<ExtensionCacheImpl>;
-
-  ExtensionCacheImpl();
-  virtual ~ExtensionCacheImpl();
-
   // Callback that is called when local cache is ready.
   void OnCacheInitialized();
 

chrome/browser/extensions/updater/extension_downloader.cc

@@ -20,7 +20,6 @@
 #include "base/time/time.h"
 #include "base/version.h"
 #include "chrome/browser/chrome_notification_types.h"
-#include "chrome/browser/extensions/updater/extension_cache.h"
 #include "chrome/browser/extensions/updater/request_queue_impl.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/chrome_version_info.h"
@@ -28,6 +27,7 @@
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_details.h"
 #include "content/public/browser/notification_service.h"
+#include "extensions/browser/updater/extension_cache.h"
 #include "extensions/browser/updater/safe_manifest_parser.h"
 #include "extensions/common/extension_urls.h"
 #include "google_apis/gaia/identity_provider.h"

chrome/browser/extensions/updater/extension_updater.cc

@@ -395,6 +395,11 @@ bool ExtensionUpdater::WillCheckSoon() const {
   return will_check_soon_;
 }
 
+void ExtensionUpdater::SetExtensionCacheForTesting(
+    ExtensionCache* extension_cache) {
+  extension_cache_ = extension_cache;
+}
+
 void ExtensionUpdater::DoCheckSoon() {
   DCHECK(will_check_soon_);
   CheckNow(default_params_);

chrome/browser/extensions/updater/extension_updater.h

@@ -125,6 +125,9 @@ class ExtensionUpdater : public ExtensionDownloaderDelegate,
     default_params_ = params;
   }
 
+  // Overrides the extension cache with |extension_cache| for testing.
+  void SetExtensionCacheForTesting(ExtensionCache* extension_cache);
+
  private:
   friend class ExtensionUpdaterTest;
   friend class ExtensionUpdaterFileHandler;

chrome/browser/policy/policy_browsertest.cc

@@ -611,6 +611,10 @@ class PolicyTest : public InProcessBrowserTest {
     BrowserThread::PostTask(
         BrowserThread::IO, FROM_HERE,
         base::Bind(chrome_browser_net::SetUrlRequestMocksEnabled, true));
+    if (extension_service()->updater()) {
+      extension_service()->updater()->SetExtensionCacheForTesting(
+          test_extension_cache_.get());
+    }
   }
 
   // Makes URLRequestMockHTTPJobs serve data from content::DIR_TEST_DATA

chrome/chrome_browser_extensions.gypi

@@ -783,8 +783,6 @@
       'browser/extensions/unpacked_installer.h',
       'browser/extensions/updater/chrome_extension_downloader_factory.cc',
       'browser/extensions/updater/chrome_extension_downloader_factory.h',
-      'browser/extensions/updater/extension_cache.cc',
-      'browser/extensions/updater/extension_cache.h',
       'browser/extensions/updater/extension_downloader.cc',
       'browser/extensions/updater/extension_downloader.h',
       'browser/extensions/updater/extension_downloader_delegate.cc',

extensions/browser/BUILD.gn

@@ -426,8 +426,11 @@ source_set("browser") {
       "suggest_permission_util.h",
       "uninstall_reason.h",
       "update_observer.h",
+      "updater/extension_cache.h",
       "updater/manifest_fetch_data.cc",
       "updater/manifest_fetch_data.h",
+      "updater/null_extension_cache.cc",
+      "updater/null_extension_cache.h",
       "updater/safe_manifest_parser.cc",
       "updater/safe_manifest_parser.h",
       "url_request_util.cc",

extensions/browser/extensions_browser_client.h

@@ -38,6 +38,7 @@ class ApiActivityMonitor;
 class AppSorting;
 class ComponentExtensionResourceManager;
 class Extension;
+class ExtensionCache;
 class ExtensionHostDelegate;
 class ExtensionPrefsObserver;
 class ExtensionSystem;
@@ -187,6 +188,9 @@ class ExtensionsBrowserClient {
   // Returns the embedder's net::NetLog.
   virtual net::NetLog* GetNetLog() = 0;
 
+  // Gets the single ExtensionCache instance shared across the browser process.
+  virtual ExtensionCache* GetExtensionCache() = 0;
+
   // Returns the single instance of |this|.
   static ExtensionsBrowserClient* Get();
 

extensions/browser/test_extensions_browser_client.cc

@@ -8,6 +8,7 @@
 #include "extensions/browser/app_sorting.h"
 #include "extensions/browser/extension_host_delegate.h"
 #include "extensions/browser/test_runtime_api_delegate.h"
+#include "extensions/browser/updater/null_extension_cache.h"
 
 using content::BrowserContext;
 
@@ -18,7 +19,8 @@ TestExtensionsBrowserClient::TestExtensionsBrowserClient(
     : main_context_(main_context),
       incognito_context_(NULL),
       process_manager_delegate_(NULL),
-      extension_system_factory_(NULL) {
+      extension_system_factory_(NULL),
+      extension_cache_(new NullExtensionCache) {
   DCHECK(main_context_);
   DCHECK(!main_context_->IsOffTheRecord());
 }
@@ -171,4 +173,8 @@ net::NetLog* TestExtensionsBrowserClient::GetNetLog() {
   return NULL;
 }
 
+ExtensionCache* TestExtensionsBrowserClient::GetExtensionCache() {
+  return extension_cache_.get();
+}
+
 }  // namespace extensions

extensions/browser/test_extensions_browser_client.h

@@ -7,6 +7,7 @@
 
 #include "base/compiler_specific.h"
 #include "extensions/browser/extensions_browser_client.h"
+#include "extensions/browser/updater/extension_cache.h"
 
 namespace extensions {
 
@@ -25,6 +26,9 @@ class TestExtensionsBrowserClient : public ExtensionsBrowserClient {
   void set_extension_system_factory(ExtensionSystemProvider* factory) {
     extension_system_factory_ = factory;
   }
+  void set_extension_cache(scoped_ptr<ExtensionCache> extension_cache) {
+    extension_cache_ = extension_cache.Pass();
+  }
 
   // Associates an incognito context with |main_context_|.
   void SetIncognitoContext(content::BrowserContext* incognito_context);
@@ -85,6 +89,7 @@ class TestExtensionsBrowserClient : public ExtensionsBrowserClient {
       const std::string& event_name,
       scoped_ptr<base::ListValue> args) override;
   virtual net::NetLog* GetNetLog() override;
+  virtual ExtensionCache* GetExtensionCache() override;
 
  private:
   content::BrowserContext* main_context_;       // Not owned.
@@ -96,6 +101,8 @@ class TestExtensionsBrowserClient : public ExtensionsBrowserClient {
   // Not owned, defaults to NULL.
   ExtensionSystemProvider* extension_system_factory_;
 
+  scoped_ptr<ExtensionCache> extension_cache_;
+
   DISALLOW_COPY_AND_ASSIGN(TestExtensionsBrowserClient);
 };
 

chrome/browser/extensions/updater/extension_cache.h → extensions/browser/updater/extension_cache.h

@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROME_BROWSER_EXTENSIONS_UPDATER_EXTENSION_CACHE_H_
-#define CHROME_BROWSER_EXTENSIONS_UPDATER_EXTENSION_CACHE_H_
+#ifndef EXTENSIONS_BROWSER_UPDATER_EXTENSION_CACHE_H_
+#define EXTENSIONS_BROWSER_UPDATER_EXTENSION_CACHE_H_
 
 #include <string>
 
@@ -16,13 +16,13 @@ namespace extensions {
 // between multiple users and profiles on the machine.
 class ExtensionCache {
  public:
-  // Return global singleton instance of ExtensionCache.
-  static ExtensionCache* GetInstance();
-
   // Callback that is invoked when the file placed when PutExtension done.
   typedef base::Callback<void(const base::FilePath& file_path,
                               bool file_ownership_passed)> PutExtensionCallback;
 
+  ExtensionCache() {}
+  virtual ~ExtensionCache() {}
+
   // Initialize cache in background. The |callback| is called when cache ready.
   // Can be called multiple times. The |callback| can be called immediately if
   // cache is ready.
@@ -54,14 +54,10 @@ class ExtensionCache {
                             const std::string& version,
                             const PutExtensionCallback& callback) = 0;
 
- protected:
-  virtual ~ExtensionCache() {}
-
-  // Sets the singleton to the given |cache|. Returns the previous value of
-  // the singleton. Ownership is not transferred.
-  static ExtensionCache* SetForTesting(ExtensionCache* cache);
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ExtensionCache);
 };
 
 }  // namespace extensions
 
-#endif  // CHROME_BROWSER_EXTENSIONS_UPDATER_EXTENSION_CACHE_H_
+#endif  // EXTENSIONS_BROWSER_UPDATER_EXTENSION_CACHE_H_

extensions/browser/updater/null_extension_cache.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "extensions/browser/updater/null_extension_cache.h"
+
+#include "base/callback.h"
+
+namespace extensions {
+
+NullExtensionCache::NullExtensionCache() {
+}
+
+NullExtensionCache::~NullExtensionCache() {
+}
+
+void NullExtensionCache::Start(const base::Closure& callback) {
+  callback.Run();
+}
+
+void NullExtensionCache::Shutdown(const base::Closure& callback) {
+  callback.Run();
+}
+
+void NullExtensionCache::AllowCaching(const std::string& id) {
+}
+
+bool NullExtensionCache::GetExtension(const std::string& id,
+                                      base::FilePath* file_path,
+                                      std::string* version) {
+  return false;
+}
+
+void NullExtensionCache::PutExtension(const std::string& id,
+                                      const base::FilePath& file_path,
+                                      const std::string& version,
+                                      const PutExtensionCallback& callback) {
+  callback.Run(file_path, true);
+}
+
+}  // namespace extensions

extensions/browser/updater/null_extension_cache.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef EXTENSIONS_BROWSER_UPDATER_NULL_EXTENSION_CACHE_H_
+#define EXTENSIONS_BROWSER_UPDATER_NULL_EXTENSION_CACHE_H_
+
+#include "extensions/browser/updater/extension_cache.h"
+
+namespace extensions {
+
+// Implements a pass-thru (i.e. do-nothing) ExtensionCache.
+class NullExtensionCache : public ExtensionCache {
+ public:
+  NullExtensionCache();
+  virtual ~NullExtensionCache();
+
+  // ExtensionCache implementation.
+  virtual void Start(const base::Closure& callback) override;
+  virtual void Shutdown(const base::Closure& callback) override;
+  virtual void AllowCaching(const std::string& id) override;
+  virtual bool GetExtension(const std::string& id,
+                            base::FilePath* file_path,
+                            std::string* version) override;
+  virtual void PutExtension(const std::string& id,
+                            const base::FilePath& file_path,
+                            const std::string& version,
+                            const PutExtensionCallback& callback) override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(NullExtensionCache);
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_BROWSER_UPDATER_NULL_EXTENSION_CACHE_H_

extensions/extensions.gyp

@@ -714,8 +714,11 @@
         'browser/suggest_permission_util.h',
         'browser/uninstall_reason.h',
         'browser/update_observer.h',
+        'browser/updater/extension_cache.h',
         'browser/updater/manifest_fetch_data.cc',
         'browser/updater/manifest_fetch_data.h',
+        'browser/updater/null_extension_cache.cc',
+        'browser/updater/null_extension_cache.h',
         'browser/updater/safe_manifest_parser.cc',
         'browser/updater/safe_manifest_parser.h',
         'browser/url_request_util.cc',

extensions/shell/browser/shell_extensions_browser_client.cc

@@ -17,6 +17,7 @@
 #include "extensions/browser/extension_function_registry.h"
 #include "extensions/browser/extension_prefs.h"
 #include "extensions/browser/null_app_sorting.h"
+#include "extensions/browser/updater/null_extension_cache.h"
 #include "extensions/browser/url_request_util.h"
 #include "extensions/shell/browser/shell_extension_host_delegate.h"
 #include "extensions/shell/browser/shell_extension_system_factory.h"
@@ -37,7 +38,9 @@ void RegisterPrefs(user_prefs::PrefRegistrySyncable* registry) {
 
 ShellExtensionsBrowserClient::ShellExtensionsBrowserClient(
     BrowserContext* context)
-    : browser_context_(context), api_client_(new ExtensionsAPIClient) {
+    : browser_context_(context),
+      api_client_(new ExtensionsAPIClient),
+      extension_cache_(new NullExtensionCache()) {
   // Set up the preferences service.
   base::PrefServiceFactory factory;
   factory.set_user_prefs(new TestingPrefStore);
@@ -219,4 +222,8 @@ net::NetLog* ShellExtensionsBrowserClient::GetNetLog() {
   return NULL;
 }
 
+ExtensionCache* ShellExtensionsBrowserClient::GetExtensionCache() {
+  return extension_cache_.get();
+}
+
 }  // namespace extensions

extensions/shell/browser/shell_extensions_browser_client.h

@@ -78,6 +78,7 @@ class ShellExtensionsBrowserClient : public ExtensionsBrowserClient {
       const std::string& event_name,
       scoped_ptr<base::ListValue> args) override;
   virtual net::NetLog* GetNetLog() override;
+  virtual ExtensionCache* GetExtensionCache() override;
 
  private:
   // The single BrowserContext for app_shell. Not owned.
@@ -89,6 +90,9 @@ class ShellExtensionsBrowserClient : public ExtensionsBrowserClient {
   // The PrefService for |browser_context_|.
   scoped_ptr<PrefService> prefs_;
 
+  // The extension cache used for download and installation.
+  scoped_ptr<ExtensionCache> extension_cache_;
+
   DISALLOW_COPY_AND_ASSIGN(ShellExtensionsBrowserClient);
 };