Add chrome.power extension API.

This moves the chrome.experimental.power API to
chrome.power, makes minor changes to its public interface
(adding a "level" parameter to requestKeepAwake() and
removing the callbacks from both methods), adds unit tests
for it, and adds a sample "Keep Awake" extension meant to
replace the existing Chrome OS-specific extension at
http://goo.gl/CrUzi.

BUG=178944
TBR=sky@chromium.org

Review URL: https://chromiumcodereview.appspot.com/12576018

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@189253 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 534 insertions, 0 deletions

diff --git a/chrome/browser/extensions/api/power/power_api.cc b/chrome/browser/extensions/api/power/power_api.cc
new file mode 100644
index 0000000..e82e4b5
--- /dev/null
+++ b/chrome/browser/extensions/api/power/power_api.cc
@@ -0,0 +1,26 @@
+// Copyright (c) 2013 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/api/power/power_api.h"
+
+#include "chrome/browser/extensions/api/power/power_api_manager.h"
+#include "chrome/common/extensions/api/power.h"
+
+namespace extensions {
+
+bool PowerRequestKeepAwakeFunction::RunImpl() {
+  scoped_ptr<api::power::RequestKeepAwake::Params> params(
+      api::power::RequestKeepAwake::Params::Create(*args_));
+  EXTENSION_FUNCTION_VALIDATE(params);
+  EXTENSION_FUNCTION_VALIDATE(params->level != api::power::LEVEL_NONE);
+  PowerApiManager::GetInstance()->AddRequest(extension_id(), params->level);
+  return true;
+}
+
+bool PowerReleaseKeepAwakeFunction::RunImpl() {
+  PowerApiManager::GetInstance()->RemoveRequest(extension_id());
+  return true;
+}
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/api/power/power_api.h b/chrome/browser/extensions/api/power/power_api.h
new file mode 100644
index 0000000..fcde9c5
--- /dev/null
+++ b/chrome/browser/extensions/api/power/power_api.h
@@ -0,0 +1,38 @@
+// Copyright (c) 2012 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 CHROME_BROWSER_EXTENSIONS_API_POWER_POWER_API_H_
+#define CHROME_BROWSER_EXTENSIONS_API_POWER_POWER_API_H_
+
+#include "chrome/browser/extensions/extension_function.h"
+
+namespace extensions {
+
+// Implementation of the chrome.power.requestKeepAwake API.
+class PowerRequestKeepAwakeFunction : public SyncExtensionFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION("power.requestKeepAwake", POWER_REQUESTKEEPAWAKE)
+
+ protected:
+  virtual ~PowerRequestKeepAwakeFunction() {}
+
+  // ExtensionFunction:
+  virtual bool RunImpl() OVERRIDE;
+};
+
+// Implementation of the chrome.power.releaseKeepAwake API.
+class PowerReleaseKeepAwakeFunction : public SyncExtensionFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION("power.releaseKeepAwake", POWER_RELEASEKEEPAWAKE)
+
+ protected:
+  virtual ~PowerReleaseKeepAwakeFunction() {}
+
+  // ExtensionFunction:
+  virtual bool RunImpl() OVERRIDE;
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_API_POWER_POWER_API_H_
diff --git a/chrome/browser/extensions/api/power/power_api_manager.cc b/chrome/browser/extensions/api/power/power_api_manager.cc
new file mode 100644
index 0000000..1a1c37b
--- /dev/null
+++ b/chrome/browser/extensions/api/power/power_api_manager.cc
@@ -0,0 +1,109 @@
+// Copyright (c) 2013 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/api/power/power_api_manager.h"
+
+#include "base/bind.h"
+#include "chrome/common/chrome_notification_types.h"
+#include "chrome/common/extensions/extension.h"
+#include "content/public/browser/notification_service.h"
+
+namespace extensions {
+
+namespace {
+
+const char kPowerSaveBlockerReason[] = "extension";
+
+content::PowerSaveBlocker::PowerSaveBlockerType
+LevelToPowerSaveBlockerType(api::power::Level level) {
+  switch (level) {
+    case api::power::LEVEL_SYSTEM:
+      return content::PowerSaveBlocker::kPowerSaveBlockPreventAppSuspension;
+    case api::power::LEVEL_DISPLAY:  // fallthrough
+    case api::power::LEVEL_NONE:
+      return content::PowerSaveBlocker::kPowerSaveBlockPreventDisplaySleep;
+  }
+  NOTREACHED() << "Unhandled level " << level;
+  return content::PowerSaveBlocker::kPowerSaveBlockPreventDisplaySleep;
+}
+
+}  // namespace
+
+// static
+PowerApiManager* PowerApiManager::GetInstance() {
+  return Singleton<PowerApiManager>::get();
+}
+
+void PowerApiManager::AddRequest(const std::string& extension_id,
+                                 api::power::Level level) {
+  extension_levels_[extension_id] = level;
+  UpdatePowerSaveBlocker();
+}
+
+void PowerApiManager::RemoveRequest(const std::string& extension_id) {
+  extension_levels_.erase(extension_id);
+  UpdatePowerSaveBlocker();
+}
+
+void PowerApiManager::SetCreateBlockerFunctionForTesting(
+    CreateBlockerFunction function) {
+  create_blocker_function_ = !function.is_null() ? function :
+      base::Bind(&content::PowerSaveBlocker::Create);
+}
+
+void PowerApiManager::Observe(int type,
+                              const content::NotificationSource& source,
+                              const content::NotificationDetails& details) {
+  switch (type) {
+    case chrome::NOTIFICATION_EXTENSION_UNLOADED:
+      RemoveRequest(content::Details<extensions::UnloadedExtensionInfo>(
+          details)->extension->id());
+      UpdatePowerSaveBlocker();
+      break;
+    case chrome::NOTIFICATION_APP_TERMINATING:
+      power_save_blocker_.reset();
+      break;
+    default:
+      NOTREACHED() << "Unexpected notification " << type;
+  }
+}
+
+PowerApiManager::PowerApiManager()
+    : create_blocker_function_(base::Bind(&content::PowerSaveBlocker::Create)),
+      current_level_(api::power::LEVEL_SYSTEM) {
+  registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_UNLOADED,
+                  content::NotificationService::AllSources());
+  registrar_.Add(this, chrome::NOTIFICATION_APP_TERMINATING,
+                 content::NotificationService::AllSources());
+}
+
+PowerApiManager::~PowerApiManager() {}
+
+void PowerApiManager::UpdatePowerSaveBlocker() {
+  if (extension_levels_.empty()) {
+    power_save_blocker_.reset();
+    return;
+  }
+
+  api::power::Level new_level = api::power::LEVEL_SYSTEM;
+  for (ExtensionLevelMap::const_iterator it = extension_levels_.begin();
+       it != extension_levels_.end(); ++it) {
+    if (it->second == api::power::LEVEL_DISPLAY)
+      new_level = it->second;
+  }
+
+  // If the level changed and we need to create a new blocker, do a swap
+  // to ensure that there isn't a brief period where power management is
+  // unblocked.
+  if (!power_save_blocker_ || new_level != current_level_) {
+    content::PowerSaveBlocker::PowerSaveBlockerType type =
+        LevelToPowerSaveBlockerType(new_level);
+    scoped_ptr<content::PowerSaveBlocker> new_blocker(
+        create_blocker_function_.Run(type, kPowerSaveBlockerReason));
+    power_save_blocker_.swap(new_blocker);
+    current_level_ = new_level;
+  }
+}
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/api/power/power_api_manager.h b/chrome/browser/extensions/api/power/power_api_manager.h
new file mode 100644
index 0000000..48ed9ee
--- /dev/null
+++ b/chrome/browser/extensions/api/power/power_api_manager.h
@@ -0,0 +1,79 @@
+// Copyright (c) 2013 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 CHROME_BROWSER_EXTENSIONS_API_POWER_POWER_API_MANAGER_H_
+#define CHROME_BROWSER_EXTENSIONS_API_POWER_POWER_API_MANAGER_H_
+
+#include <map>
+#include <string>
+
+#include "base/callback.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/singleton.h"
+#include "chrome/common/extensions/api/power.h"
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
+#include "content/public/browser/power_save_blocker.h"
+
+namespace extensions {
+
+class PowerApiManager : public content::NotificationObserver {
+ public:
+  typedef base::Callback<scoped_ptr<content::PowerSaveBlocker>(
+      content::PowerSaveBlocker::PowerSaveBlockerType,
+      const std::string&)> CreateBlockerFunction;
+
+  static PowerApiManager* GetInstance();
+
+  // Adds an extension lock at |level| for |extension_id|, replacing the
+  // extension's existing lock, if any.
+  void AddRequest(const std::string& extension_id, api::power::Level level);
+
+  // Removes an extension lock for an extension. Calling this for an
+  // extension id without a lock will do nothing.
+  void RemoveRequest(const std::string& extension_id);
+
+  // Replaces the function that will be called to create PowerSaveBlocker
+  // objects.  Passing an empty callback will revert to the default.
+  void SetCreateBlockerFunctionForTesting(CreateBlockerFunction function);
+
+  // Overridden from content::NotificationObserver.
+  virtual void Observe(int type,
+                       const content::NotificationSource& source,
+                       const content::NotificationDetails& details) OVERRIDE;
+
+ private:
+  friend struct DefaultSingletonTraits<PowerApiManager>;
+
+  PowerApiManager();
+  virtual ~PowerApiManager();
+
+  // Updates |power_save_blocker_| and |current_level_| after iterating
+  // over |extension_levels_|.
+  void UpdatePowerSaveBlocker();
+
+  content::NotificationRegistrar registrar_;
+
+  // Function that should be called to create PowerSaveBlocker objects.
+  // Tests can change this to record what would've been done instead of
+  // actually changing the system power-saving settings.
+  CreateBlockerFunction create_blocker_function_;
+
+  scoped_ptr<content::PowerSaveBlocker> power_save_blocker_;
+
+  // Current level used by |power_save_blocker_|.  Meaningless if
+  // |power_save_blocker_| is NULL.
+  api::power::Level current_level_;
+
+  // Map from extension ID to the corresponding level for each extension
+  // that has an outstanding request.
+  typedef std::map<std::string, api::power::Level> ExtensionLevelMap;
+  ExtensionLevelMap extension_levels_;
+
+  DISALLOW_COPY_AND_ASSIGN(PowerApiManager);
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_API_POWER_POWER_API_MANAGER_H_
diff --git a/chrome/browser/extensions/api/power/power_api_unittest.cc b/chrome/browser/extensions/api/power/power_api_unittest.cc
new file mode 100644
index 0000000..7c2ce9a
--- /dev/null
+++ b/chrome/browser/extensions/api/power/power_api_unittest.cc
@@ -0,0 +1,282 @@
+// Copyright (c) 2013 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/api/power/power_api.h"
+
+#include <deque>
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "chrome/browser/extensions/api/power/power_api_manager.h"
+#include "chrome/browser/extensions/extension_function_test_utils.h"
+#include "chrome/common/chrome_notification_types.h"
+#include "chrome/common/extensions/extension.h"
+#include "chrome/test/base/browser_with_test_window_test.h"
+#include "content/public/browser/power_save_blocker.h"
+
+namespace utils = extension_function_test_utils;
+
+namespace extensions {
+
+namespace {
+
+// Args commonly passed to PowerSaveBlockerStubManager::CallFunction().
+const char kDisplayArgs[] = "[\"display\"]";
+const char kSystemArgs[] = "[\"system\"]";
+const char kEmptyArgs[] = "[]";
+
+// Different actions that can be performed as a result of a
+// PowerSaveBlocker being created or destroyed.
+enum Request {
+  BLOCK_APP_SUSPENSION,
+  UNBLOCK_APP_SUSPENSION,
+  BLOCK_DISPLAY_SLEEP,
+  UNBLOCK_DISPLAY_SLEEP,
+  // Returned by PowerSaveBlockerStubManager::PopFirstRequest() when no
+  // requests are present.
+  NONE,
+};
+
+// Stub implementation of content::PowerSaveBlocker that just runs a
+// callback on destruction.
+class PowerSaveBlockerStub : public content::PowerSaveBlocker {
+ public:
+  explicit PowerSaveBlockerStub(base::Closure unblock_callback)
+      : unblock_callback_(unblock_callback) {
+  }
+
+  virtual ~PowerSaveBlockerStub() {
+    unblock_callback_.Run();
+  }
+
+ private:
+  base::Closure unblock_callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(PowerSaveBlockerStub);
+};
+
+// Manages PowerSaveBlockerStub objects.  Tests can instantiate this class
+// to make PowerApiManager's calls to create PowerSaveBlockers record the
+// actions that would've been performed instead of actually blocking and
+// unblocking power management.
+class PowerSaveBlockerStubManager {
+ public:
+  PowerSaveBlockerStubManager() : weak_ptr_factory_(this) {
+    // Use base::Unretained since callbacks with return values can't use
+    // weak pointers.
+    PowerApiManager::GetInstance()->SetCreateBlockerFunctionForTesting(
+        base::Bind(&PowerSaveBlockerStubManager::CreateStub,
+                   base::Unretained(this)));
+  }
+
+  ~PowerSaveBlockerStubManager() {
+    PowerApiManager::GetInstance()->SetCreateBlockerFunctionForTesting(
+        PowerApiManager::CreateBlockerFunction());
+  }
+
+  // Removes and returns the first item from |requests_|.  Returns NONE if
+  // |requests_| is empty.
+  Request PopFirstRequest() {
+    if (requests_.empty())
+      return NONE;
+
+    Request request = requests_.front();
+    requests_.pop_front();
+    return request;
+  }
+
+ private:
+  // Creates a new PowerSaveBlockerStub of type |type|.
+  scoped_ptr<content::PowerSaveBlocker> CreateStub(
+      content::PowerSaveBlocker::PowerSaveBlockerType type,
+      const std::string& reason) {
+    Request unblock_request = NONE;
+    switch (type) {
+      case content::PowerSaveBlocker::kPowerSaveBlockPreventAppSuspension:
+        requests_.push_back(BLOCK_APP_SUSPENSION);
+        unblock_request = UNBLOCK_APP_SUSPENSION;
+        break;
+      case content::PowerSaveBlocker::kPowerSaveBlockPreventDisplaySleep:
+        requests_.push_back(BLOCK_DISPLAY_SLEEP);
+        unblock_request = UNBLOCK_DISPLAY_SLEEP;
+        break;
+    }
+    return scoped_ptr<content::PowerSaveBlocker>(
+        new PowerSaveBlockerStub(
+            base::Bind(&PowerSaveBlockerStubManager::AppendRequest,
+                       weak_ptr_factory_.GetWeakPtr(),
+                       unblock_request)));
+  }
+
+  void AppendRequest(Request request) {
+    requests_.push_back(request);
+  }
+
+  // Requests in chronological order.
+  std::deque<Request> requests_;
+
+  base::WeakPtrFactory<PowerSaveBlockerStubManager> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(PowerSaveBlockerStubManager);
+};
+
+}  // namespace
+
+class PowerApiTest : public BrowserWithTestWindowTest {
+ public:
+  virtual void SetUp() OVERRIDE {
+    BrowserWithTestWindowTest::SetUp();
+    manager_.reset(new PowerSaveBlockerStubManager);
+    extension_ = utils::CreateEmptyExtensionWithLocation(
+        extensions::Manifest::UNPACKED);
+  }
+
+ protected:
+  // Shorthand for PowerRequestKeepAwakeFunction and
+  // PowerReleaseKeepAwakeFunction.
+  enum FunctionType {
+    REQUEST,
+    RELEASE,
+  };
+
+  // Calls the function described by |type| with |args|, a JSON list of
+  // arguments, on behalf of |extension|.
+  bool CallFunction(FunctionType type,
+                    const std::string& args,
+                    extensions::Extension* extension) {
+    UIThreadExtensionFunction* function =
+        type == REQUEST ?
+        static_cast<UIThreadExtensionFunction*>(
+            new PowerRequestKeepAwakeFunction) :
+        static_cast<UIThreadExtensionFunction*>(
+            new PowerReleaseKeepAwakeFunction);
+    function->set_extension(extension);
+    return utils::RunFunction(function, args, browser(), utils::NONE);
+  }
+
+  // Send a notification to PowerApiManager saying that |extension| has
+  // been unloaded.
+  void UnloadExtension(extensions::Extension* extension) {
+    UnloadedExtensionInfo details(
+        extension, extension_misc::UNLOAD_REASON_UNINSTALL);
+    PowerApiManager::GetInstance()->Observe(
+        chrome::NOTIFICATION_EXTENSION_UNLOADED,
+        content::Source<Profile>(browser()->profile()),
+        content::Details<UnloadedExtensionInfo>(&details));
+  }
+
+  scoped_ptr<PowerSaveBlockerStubManager> manager_;
+  scoped_refptr<extensions::Extension> extension_;
+};
+
+TEST_F(PowerApiTest, RequestAndRelease) {
+  // Simulate an extension making and releasing a "display" request and a
+  // "system" request.
+  ASSERT_TRUE(CallFunction(REQUEST, kDisplayArgs, extension_.get()));
+  EXPECT_EQ(BLOCK_DISPLAY_SLEEP, manager_->PopFirstRequest());
+  EXPECT_EQ(NONE, manager_->PopFirstRequest());
+  ASSERT_TRUE(CallFunction(RELEASE, kEmptyArgs, extension_.get()));
+  EXPECT_EQ(UNBLOCK_DISPLAY_SLEEP, manager_->PopFirstRequest());
+  EXPECT_EQ(NONE, manager_->PopFirstRequest());
+
+  ASSERT_TRUE(CallFunction(REQUEST, kSystemArgs, extension_.get()));
+  EXPECT_EQ(BLOCK_APP_SUSPENSION, manager_->PopFirstRequest());
+  EXPECT_EQ(NONE, manager_->PopFirstRequest());
+  ASSERT_TRUE(CallFunction(RELEASE, kEmptyArgs, extension_.get()));
+  EXPECT_EQ(UNBLOCK_APP_SUSPENSION, manager_->PopFirstRequest());
+  EXPECT_EQ(NONE, manager_->PopFirstRequest());
+}
+
+TEST_F(PowerApiTest, RequestWithoutRelease) {
+  // Simulate an extension calling requestKeepAwake() without calling
+  // releaseKeepAwake().  The override should be automatically removed when
+  // the extension is unloaded.
+  ASSERT_TRUE(CallFunction(REQUEST, kDisplayArgs, extension_.get()));
+  EXPECT_EQ(BLOCK_DISPLAY_SLEEP, manager_->PopFirstRequest());
+  EXPECT_EQ(NONE, manager_->PopFirstRequest());
+
+  UnloadExtension(extension_.get());
+  EXPECT_EQ(UNBLOCK_DISPLAY_SLEEP, manager_->PopFirstRequest());
+  EXPECT_EQ(NONE, manager_->PopFirstRequest());
+}
+
+TEST_F(PowerApiTest, ReleaseWithoutRequest) {
+  // Simulate an extension calling releaseKeepAwake() without having
+  // calling requestKeepAwake() earlier.  The call should be ignored.
+  ASSERT_TRUE(CallFunction(RELEASE, kEmptyArgs, extension_.get()));
+  EXPECT_EQ(NONE, manager_->PopFirstRequest());
+}
+
+TEST_F(PowerApiTest, UpgradeRequest) {
+  // Simulate an extension calling requestKeepAwake("system") and then
+  // requestKeepAwake("display").  When the second call is made, a
+  // display-sleep-blocking request should be made before the initial
+  // app-suspension-blocking request is released.
+  ASSERT_TRUE(CallFunction(REQUEST, kSystemArgs, extension_.get()));
+  EXPECT_EQ(BLOCK_APP_SUSPENSION, manager_->PopFirstRequest());
+  EXPECT_EQ(NONE, manager_->PopFirstRequest());
+
+  ASSERT_TRUE(CallFunction(REQUEST, kDisplayArgs, extension_.get()));
+  EXPECT_EQ(BLOCK_DISPLAY_SLEEP, manager_->PopFirstRequest());
+  EXPECT_EQ(UNBLOCK_APP_SUSPENSION, manager_->PopFirstRequest());
+  EXPECT_EQ(NONE, manager_->PopFirstRequest());
+
+  ASSERT_TRUE(CallFunction(RELEASE, kEmptyArgs, extension_.get()));
+  EXPECT_EQ(UNBLOCK_DISPLAY_SLEEP, manager_->PopFirstRequest());
+  EXPECT_EQ(NONE, manager_->PopFirstRequest());
+}
+
+TEST_F(PowerApiTest, DowngradeRequest) {
+  // Simulate an extension calling requestKeepAwake("display") and then
+  // requestKeepAwake("system").  When the second call is made, an
+  // app-suspension-blocking request should be made before the initial
+  // display-sleep-blocking request is released.
+  ASSERT_TRUE(CallFunction(REQUEST, kDisplayArgs, extension_.get()));
+  EXPECT_EQ(BLOCK_DISPLAY_SLEEP, manager_->PopFirstRequest());
+  EXPECT_EQ(NONE, manager_->PopFirstRequest());
+
+  ASSERT_TRUE(CallFunction(REQUEST, kSystemArgs, extension_.get()));
+  EXPECT_EQ(BLOCK_APP_SUSPENSION, manager_->PopFirstRequest());
+  EXPECT_EQ(UNBLOCK_DISPLAY_SLEEP, manager_->PopFirstRequest());
+  EXPECT_EQ(NONE, manager_->PopFirstRequest());
+
+  ASSERT_TRUE(CallFunction(RELEASE, kEmptyArgs, extension_.get()));
+  EXPECT_EQ(UNBLOCK_APP_SUSPENSION, manager_->PopFirstRequest());
+  EXPECT_EQ(NONE, manager_->PopFirstRequest());
+}
+
+TEST_F(PowerApiTest, MultipleExtensions) {
+  // Simulate an extension blocking the display from sleeping.
+  ASSERT_TRUE(CallFunction(REQUEST, kDisplayArgs, extension_.get()));
+  EXPECT_EQ(BLOCK_DISPLAY_SLEEP, manager_->PopFirstRequest());
+  EXPECT_EQ(NONE, manager_->PopFirstRequest());
+
+  // Create a second extension that blocks system suspend.  No additional
+  // PowerSaveBlocker is needed; the blocker from the first extension
+  // already covers the behavior requested by the second extension.
+  scoped_ptr<base::DictionaryValue> extension_value(
+      utils::ParseDictionary("{\"name\": \"Test\", \"version\": \"1.0\"}"));
+  scoped_refptr<extensions::Extension> extension2(
+      utils::CreateExtension(extensions::Manifest::UNPACKED,
+                             extension_value.get(), "second_extension"));
+  ASSERT_TRUE(CallFunction(REQUEST, kSystemArgs, extension2.get()));
+  EXPECT_EQ(NONE, manager_->PopFirstRequest());
+
+  // When the first extension is unloaded, a new app-suspension blocker
+  // should be created before the display-sleep blocker is destroyed.
+  UnloadExtension(extension_.get());
+  EXPECT_EQ(BLOCK_APP_SUSPENSION, manager_->PopFirstRequest());
+  EXPECT_EQ(UNBLOCK_DISPLAY_SLEEP, manager_->PopFirstRequest());
+  EXPECT_EQ(NONE, manager_->PopFirstRequest());
+
+  // Make the first extension block display-sleep again.
+  ASSERT_TRUE(CallFunction(REQUEST, kDisplayArgs, extension_.get()));
+  EXPECT_EQ(BLOCK_DISPLAY_SLEEP, manager_->PopFirstRequest());
+  EXPECT_EQ(UNBLOCK_APP_SUSPENSION, manager_->PopFirstRequest());
+  EXPECT_EQ(NONE, manager_->PopFirstRequest());
+}
+
+}  // namespace extensions