Add a data source field for volumes.

Especially for FSP, we'd like to know type of a volume, as the way they are
going to be displayed in Files app depends on it. Eg. SOURCE_FILE volumes will
be auto opened once they are mounted. SOURCE_NETWORK file systems will have
a button for configuration.

TEST=unit_tests, browser_tests
BUG=474146

Review URL: https://codereview.chromium.org/1055183003

Cr-Commit-Position: refs/heads/master@{#324429}

14 files changed, 247 insertions, 11 deletions

diff --git a/chrome/browser/chromeos/extensions/file_manager/private_api_util.cc b/chrome/browser/chromeos/extensions/file_manager/private_api_util.cc
index c4e4195..1b71ef0 100644
--- a/chrome/browser/chromeos/extensions/file_manager/private_api_util.cc
+++ b/chrome/browser/chromeos/extensions/file_manager/private_api_util.cc
@@ -182,9 +182,25 @@ void VolumeToVolumeMetadata(
         new std::string(volume.source_path().AsUTF8Unsafe()));
   }
 
+  switch (volume.volume_source()) {
+    case VOLUME_SOURCE_UNKNOWN:
+      volume_metadata->volume_source = file_manager_private::VOLUME_SOURCE_NONE;
+      break;
+    case VOLUME_SOURCE_FILE:
+      volume_metadata->volume_source = file_manager_private::VOLUME_SOURCE_FILE;
+      break;
+    case VOLUME_SOURCE_DEVICE:
+      volume_metadata->volume_source =
+          file_manager_private::VOLUME_SOURCE_DEVICE;
+      break;
+    case VOLUME_SOURCE_NETWORK:
+      volume_metadata->volume_source =
+          file_manager_private::VOLUME_SOURCE_NETWORK;
+      break;
+  }
+
   if (volume.type() == VOLUME_TYPE_PROVIDED) {
     volume_metadata->extension_id.reset(new std::string(volume.extension_id()));
-
     volume_metadata->file_system_id.reset(
         new std::string(volume.file_system_id()));
   }
diff --git a/chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.cc b/chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.cc
index 09a8920..643bb3d 100644
--- a/chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.cc
+++ b/chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.cc
@@ -70,6 +70,22 @@ scoped_ptr<ProvidedFileSystemObserver::Changes> ParseChanges(
   return results;
 }
 
+// Converts the file system source from the IDL type to a native type.
+chromeos::file_system_provider::Source ParseSource(
+    const api::file_system_provider::FileSystemSource& source) {
+  switch (source) {
+    case api::file_system_provider::FILE_SYSTEM_SOURCE_FILE:
+      return chromeos::file_system_provider::SOURCE_FILE;
+    case api::file_system_provider::FILE_SYSTEM_SOURCE_DEVICE:
+      return chromeos::file_system_provider::SOURCE_DEVICE;
+    case api::file_system_provider::FILE_SYSTEM_SOURCE_NETWORK:
+      return chromeos::file_system_provider::SOURCE_NETWORK;
+    case api::file_system_provider::FILE_SYSTEM_SOURCE_NONE:
+      return chromeos::file_system_provider::SOURCE_UNKNOWN;
+  }
+  return chromeos::file_system_provider::SOURCE_UNKNOWN;
+}
+
 // Fills the IDL's FileSystemInfo with FSP's ProvidedFileSystemInfo and
 // Watchers.
 void FillFileSystemInfo(const ProvidedFileSystemInfo& file_system_info,
@@ -83,6 +99,20 @@ void FillFileSystemInfo(const ProvidedFileSystemInfo& file_system_info,
   output->display_name = file_system_info.display_name();
   output->writable = file_system_info.writable();
   output->opened_files_limit = file_system_info.opened_files_limit();
+  switch (file_system_info.source()) {
+    case chromeos::file_system_provider::SOURCE_FILE:
+      output->source = api::file_system_provider::FILE_SYSTEM_SOURCE_FILE;
+      break;
+    case chromeos::file_system_provider::SOURCE_DEVICE:
+      output->source = api::file_system_provider::FILE_SYSTEM_SOURCE_DEVICE;
+      break;
+    case chromeos::file_system_provider::SOURCE_NETWORK:
+      output->source = api::file_system_provider::FILE_SYSTEM_SOURCE_NETWORK;
+      break;
+    case chromeos::file_system_provider::SOURCE_UNKNOWN:
+      output->source = api::file_system_provider::FILE_SYSTEM_SOURCE_NONE;
+      break;
+  }
 
   std::vector<linked_ptr<Watcher>> watcher_items;
   for (const auto& watcher : watchers) {
@@ -152,6 +182,7 @@ bool FileSystemProviderMountFunction::RunSync() {
                                    ? *params->options.opened_files_limit.get()
                                    : 0;
   options.supports_notify_tag = params->options.supports_notify_tag;
+  options.source = ParseSource(params->options.source);
 
   const base::File::Error result =
       service->MountFileSystem(extension_id(), options);
diff --git a/chrome/browser/chromeos/file_manager/volume_manager.cc b/chrome/browser/chromeos/file_manager/volume_manager.cc
index b41b65e..227cdc0 100644
--- a/chrome/browser/chromeos/file_manager/volume_manager.cc
+++ b/chrome/browser/chromeos/file_manager/volume_manager.cc
@@ -150,6 +150,7 @@ Volume* Volume::CreateForDrive(Profile* profile) {
   volume->type_ = VOLUME_TYPE_GOOGLE_DRIVE;
   volume->device_type_ = chromeos::DEVICE_TYPE_UNKNOWN;
   volume->source_path_ = drive_path;
+  volume->volume_source_ = VOLUME_SOURCE_NETWORK;
   volume->mount_path_ = drive_path;
   volume->mount_condition_ = chromeos::disks::MOUNT_CONDITION_NONE;
   volume->is_parent_ = false;
@@ -165,6 +166,7 @@ Volume* Volume::CreateForDownloads(const base::FilePath& downloads_path) {
   volume->type_ = VOLUME_TYPE_DOWNLOADS_DIRECTORY;
   volume->device_type_ = chromeos::DEVICE_TYPE_UNKNOWN;
   // Keep source_path empty.
+  volume->volume_source_ = VOLUME_SOURCE_DEVICE;
   volume->mount_path_ = downloads_path;
   volume->mount_condition_ = chromeos::disks::MOUNT_CONDITION_NONE;
   volume->is_parent_ = false;
@@ -181,6 +183,10 @@ Volume* Volume::CreateForRemovable(
   Volume* const volume = new Volume;
   volume->type_ = MountTypeToVolumeType(mount_point.mount_type);
   volume->source_path_ = base::FilePath(mount_point.source_path);
+  volume->volume_source_ =
+      mount_point.mount_type == chromeos::MOUNT_TYPE_ARCHIVE
+          ? VOLUME_SOURCE_FILE
+          : VOLUME_SOURCE_DEVICE;
   volume->mount_path_ = base::FilePath(mount_point.mount_path);
   volume->mount_condition_ = mount_point.mount_condition;
   volume->volume_label_ = volume->mount_path().BaseName().AsUTF8Unsafe();
@@ -209,6 +215,20 @@ Volume* Volume::CreateForProvidedFileSystem(
   Volume* const volume = new Volume;
   volume->file_system_id_ = file_system_info.file_system_id();
   volume->extension_id_ = file_system_info.extension_id();
+  switch (file_system_info.source()) {
+    case chromeos::file_system_provider::SOURCE_UNKNOWN:
+      volume->volume_source_ = VOLUME_SOURCE_UNKNOWN;
+      break;
+    case chromeos::file_system_provider::SOURCE_FILE:
+      volume->volume_source_ = VOLUME_SOURCE_FILE;
+      break;
+    case chromeos::file_system_provider::SOURCE_DEVICE:
+      volume->volume_source_ = VOLUME_SOURCE_DEVICE;
+      break;
+    case chromeos::file_system_provider::SOURCE_NETWORK:
+      volume->volume_source_ = VOLUME_SOURCE_NETWORK;
+      break;
+  }
   volume->volume_label_ = file_system_info.display_name();
   volume->type_ = VOLUME_TYPE_PROVIDED;
   volume->mount_path_ = file_system_info.mount_path();
@@ -234,6 +254,7 @@ Volume* Volume::CreateForMTP(const base::FilePath& mount_path,
   volume->volume_id_ = kMtpVolumeIdPrefix + label;
   volume->volume_label_ = label;
   volume->source_path_ = mount_path;
+  volume->volume_source_ = VOLUME_SOURCE_DEVICE;
   volume->device_type_ = chromeos::DEVICE_TYPE_MOBILE;
   return volume;
 }
@@ -247,6 +268,7 @@ Volume* Volume::CreateForTesting(const base::FilePath& path,
   volume->type_ = volume_type;
   volume->device_type_ = device_type;
   // Keep source_path empty.
+  volume->volume_source_ = VOLUME_SOURCE_DEVICE;
   volume->mount_path_ = path;
   volume->mount_condition_ = chromeos::disks::MOUNT_CONDITION_NONE;
   volume->is_parent_ = false;
diff --git a/chrome/browser/chromeos/file_manager/volume_manager.h b/chrome/browser/chromeos/file_manager/volume_manager.h
index efaf20f..9b7aef6 100644
--- a/chrome/browser/chromeos/file_manager/volume_manager.h
+++ b/chrome/browser/chromeos/file_manager/volume_manager.h
@@ -57,6 +57,14 @@ enum VolumeType {
   NUM_VOLUME_TYPE,
 };
 
+// Source of a volume's data.
+enum VolumeSource {
+  VOLUME_SOURCE_UNKNOWN,
+  VOLUME_SOURCE_FILE,
+  VOLUME_SOURCE_DEVICE,
+  VOLUME_SOURCE_NETWORK
+};
+
 // Says how was the mount performed, whether due to user interaction, or
 // automatic. User interaction includes both hardware (pluggins a USB stick)
 // or software (mounting a ZIP archive) interaction.
@@ -97,6 +105,7 @@ class Volume : public base::SupportsWeakPtr<Volume> {
   const std::string& volume_id() const { return volume_id_; }
   const std::string& file_system_id() const { return file_system_id_; }
   const std::string& extension_id() const { return extension_id_; }
+  const VolumeSource volume_source() const { return volume_source_; }
   VolumeType type() const { return type_; }
   chromeos::DeviceType device_type() const { return device_type_; }
   const base::FilePath& source_path() const { return source_path_; }
@@ -127,6 +136,9 @@ class Volume : public base::SupportsWeakPtr<Volume> {
   // to an empty string.
   std::string extension_id_;
 
+  // The source of the file system's data.
+  VolumeSource volume_source_;
+
   // The type of mounted volume.
   VolumeType type_;
 
diff --git a/chrome/browser/chromeos/file_system_provider/provided_file_system_info.cc b/chrome/browser/chromeos/file_system_provider/provided_file_system_info.cc
index 38dc4a5..e09e780 100644
--- a/chrome/browser/chromeos/file_system_provider/provided_file_system_info.cc
+++ b/chrome/browser/chromeos/file_system_provider/provided_file_system_info.cc
@@ -9,7 +9,10 @@ namespace chromeos {
 namespace file_system_provider {
 
 MountOptions::MountOptions()
-    : writable(false), supports_notify_tag(false), opened_files_limit(0) {
+    : writable(false),
+      source(SOURCE_UNKNOWN),
+      supports_notify_tag(false),
+      opened_files_limit(0) {
 }
 
 MountOptions::MountOptions(const std::string& file_system_id,
@@ -17,12 +20,13 @@ MountOptions::MountOptions(const std::string& file_system_id,
     : file_system_id(file_system_id),
       display_name(display_name),
       writable(false),
+      source(SOURCE_UNKNOWN),
       supports_notify_tag(false),
       opened_files_limit(0) {
 }
 
 ProvidedFileSystemInfo::ProvidedFileSystemInfo()
-    : writable_(false), supports_notify_tag_(false) {
+    : writable_(false), source_(SOURCE_UNKNOWN), supports_notify_tag_(false) {
 }
 
 ProvidedFileSystemInfo::ProvidedFileSystemInfo(
@@ -33,6 +37,7 @@ ProvidedFileSystemInfo::ProvidedFileSystemInfo(
       file_system_id_(mount_options.file_system_id),
       display_name_(mount_options.display_name),
       writable_(mount_options.writable),
+      source_(mount_options.source),
       supports_notify_tag_(mount_options.supports_notify_tag),
       opened_files_limit_(mount_options.opened_files_limit),
       mount_path_(mount_path) {
diff --git a/chrome/browser/chromeos/file_system_provider/provided_file_system_info.h b/chrome/browser/chromeos/file_system_provider/provided_file_system_info.h
index 795577c..53a610f 100644
--- a/chrome/browser/chromeos/file_system_provider/provided_file_system_info.h
+++ b/chrome/browser/chromeos/file_system_provider/provided_file_system_info.h
@@ -12,6 +12,9 @@
 namespace chromeos {
 namespace file_system_provider {
 
+// Source of the file system's contents.
+enum Source { SOURCE_UNKNOWN, SOURCE_FILE, SOURCE_DEVICE, SOURCE_NETWORK };
+
 // Options for creating the provided file system info.
 struct MountOptions {
   MountOptions();
@@ -23,6 +26,7 @@ struct MountOptions {
   std::string file_system_id;
   std::string display_name;
   bool writable;
+  Source source;
   bool supports_notify_tag;
   int opened_files_limit;
 };
@@ -42,6 +46,7 @@ class ProvidedFileSystemInfo {
   const std::string& file_system_id() const { return file_system_id_; }
   const std::string& display_name() const { return display_name_; }
   bool writable() const { return writable_; }
+  Source source() const { return source_; }
   bool supports_notify_tag() const { return supports_notify_tag_; }
   int opened_files_limit() const { return opened_files_limit_; }
   const base::FilePath& mount_path() const { return mount_path_; }
@@ -59,6 +64,9 @@ class ProvidedFileSystemInfo {
   // Whether the file system is writable or just read-only.
   bool writable_;
 
+  // Source of the file system's contents. By default SOURCE_UNKNOWN.
+  Source source_;
+
   // Supports tags for file/directory change notifications.
   bool supports_notify_tag_;
 
diff --git a/chrome/browser/chromeos/file_system_provider/registry.cc b/chrome/browser/chromeos/file_system_provider/registry.cc
index c0bf95d..f3b3cd7 100644
--- a/chrome/browser/chromeos/file_system_provider/registry.cc
+++ b/chrome/browser/chromeos/file_system_provider/registry.cc
@@ -26,6 +26,7 @@ namespace file_system_provider {
 const char kPrefKeyFileSystemId[] = "file-system-id";
 const char kPrefKeyDisplayName[] = "display-name";
 const char kPrefKeyWritable[] = "writable";
+const char kPrefKeySource[] = "source";
 const char kPrefKeySupportsNotifyTag[] = "supports-notify-tag";
 const char kPrefKeyWatchers[] = "watchers";
 const char kPrefKeyWatcherEntryPath[] = "entry-path";
@@ -40,6 +41,41 @@ void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 }
 
+std::string SourceToString(Source source) {
+  switch (source) {
+    case SOURCE_UNKNOWN:
+      return "unknown";
+    case SOURCE_FILE:
+      return "file";
+    case SOURCE_DEVICE:
+      return "device";
+    case SOURCE_NETWORK:
+      return "network";
+  }
+  NOTREACHED();
+  return std::string();
+}
+
+bool StringToSource(const std::string& source, Source* result) {
+  if (source.compare("unknown") == 0) {
+    *result = SOURCE_UNKNOWN;
+    return true;
+  }
+  if (source.compare("file") == 0) {
+    *result = SOURCE_FILE;
+    return true;
+  }
+  if (source.compare("device") == 0) {
+    *result = SOURCE_DEVICE;
+    return true;
+  }
+  if (source.compare("network") == 0) {
+    *result = SOURCE_NETWORK;
+    return true;
+  }
+  return false;
+}
+
 Registry::Registry(Profile* profile) : profile_(profile) {
 }
 
@@ -56,6 +92,8 @@ void Registry::RememberFileSystem(
                                              file_system_info.display_name());
   file_system->SetBooleanWithoutPathExpansion(kPrefKeyWritable,
                                               file_system_info.writable());
+  file_system->SetStringWithoutPathExpansion(
+      kPrefKeySource, SourceToString(file_system_info.source()));
   file_system->SetBooleanWithoutPathExpansion(
       kPrefKeySupportsNotifyTag, file_system_info.supports_notify_tag());
   file_system->SetIntegerWithoutPathExpansion(
@@ -153,6 +191,8 @@ scoped_ptr<Registry::RestoredFileSystems> Registry::RestoreFileSystems(
     bool writable = false;
     bool supports_notify_tag = false;
     int opened_files_limit = 0;
+    std::string source_as_string;
+    Source source = SOURCE_UNKNOWN;
 
     // TODO(mtomasz): Move opened files limit to the mandatory list above in
     // M42.
@@ -166,9 +206,12 @@ scoped_ptr<Registry::RestoredFileSystems> Registry::RestoreFileSystems(
          !file_system->GetBooleanWithoutPathExpansion(kPrefKeySupportsNotifyTag,
                                                       &supports_notify_tag) ||
          file_system_id.empty() || display_name.empty()) ||
+        // Optional fields.
         (file_system->GetIntegerWithoutPathExpansion(kPrefKeyOpenedFilesLimit,
                                                      &opened_files_limit) &&
-         opened_files_limit < 0)) {
+         (file_system->GetStringWithoutPathExpansion(kPrefKeySource,
+                                                     &source_as_string) &&
+          !StringToSource(source_as_string, &source)))) {
       LOG(ERROR)
           << "Malformed provided file system information in preferences.";
       continue;
@@ -178,6 +221,7 @@ scoped_ptr<Registry::RestoredFileSystems> Registry::RestoreFileSystems(
     options.file_system_id = file_system_id;
     options.display_name = display_name;
     options.writable = writable;
+    options.source = source;
     options.supports_notify_tag = supports_notify_tag;
     options.opened_files_limit = opened_files_limit;
 
diff --git a/chrome/browser/chromeos/file_system_provider/registry.h b/chrome/browser/chromeos/file_system_provider/registry.h
index 0483e45..9072905 100644
--- a/chrome/browser/chromeos/file_system_provider/registry.h
+++ b/chrome/browser/chromeos/file_system_provider/registry.h
@@ -24,6 +24,7 @@ namespace file_system_provider {
 extern const char kPrefKeyFileSystemId[];
 extern const char kPrefKeyDisplayName[];
 extern const char kPrefKeyWritable[];
+extern const char kPrefKeySource[];
 extern const char kPrefKeySupportsNotifyTag[];
 extern const char kPrefKeyWatchers[];
 extern const char kPrefKeyWatcherEntryPath[];
@@ -37,6 +38,11 @@ class ProvidedFileSystemInfo;
 // Registers preferences to remember registered file systems between reboots.
 void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
 
+// Converts a file system's data source value back and forth between Source and
+// std::string types.
+std::string SourceToString(Source source);
+bool StringToSource(const std::string& source, Source* result);
+
 // Remembers and restores file systems in a persistent storage.
 class Registry : public RegistryInterface {
  public:
diff --git a/chrome/browser/chromeos/file_system_provider/registry_unittest.cc b/chrome/browser/chromeos/file_system_provider/registry_unittest.cc
index b02359f..8d58371 100644
--- a/chrome/browser/chromeos/file_system_provider/registry_unittest.cc
+++ b/chrome/browser/chromeos/file_system_provider/registry_unittest.cc
@@ -29,6 +29,7 @@ const char kPersistentOrigin[] =
     "chrome-extension://efgefgefgefgefgefgefgefgefgefgefgefge/";
 const char kExtensionId[] = "mbflcebpggnecokmikipoihdbecnjfoj";
 const char kDisplayName[] = "Camera Pictures";
+const Source kSource = SOURCE_NETWORK;
 
 // The dot in the file system ID is there in order to check that saving to
 // preferences works correctly. File System ID is used as a key in
@@ -44,6 +45,7 @@ void RememberFakeFileSystem(TestingProfile* profile,
                             const std::string& file_system_id,
                             const std::string& display_name,
                             bool writable,
+                            Source source,
                             bool supports_notify_tag,
                             int opened_files_limit,
                             const Watcher& watcher) {
@@ -60,6 +62,8 @@ void RememberFakeFileSystem(TestingProfile* profile,
                                              kFileSystemId);
   file_system->SetStringWithoutPathExpansion(kPrefKeyDisplayName, kDisplayName);
   file_system->SetBooleanWithoutPathExpansion(kPrefKeyWritable, writable);
+  file_system->SetStringWithoutPathExpansion(kPrefKeySource,
+                                             SourceToString(source));
   file_system->SetBooleanWithoutPathExpansion(kPrefKeySupportsNotifyTag,
                                               supports_notify_tag);
   file_system->SetIntegerWithoutPathExpansion(kPrefKeyOpenedFilesLimit,
@@ -124,8 +128,9 @@ class FileSystemProviderRegistryTest : public testing::Test {
 TEST_F(FileSystemProviderRegistryTest, RestoreFileSystems) {
   // Create a fake entry in the preferences.
   RememberFakeFileSystem(profile_, kExtensionId, kFileSystemId, kDisplayName,
-                         true /* writable */, true /* supports_notify_tag */,
-                         kOpenedFilesLimit, fake_watcher_);
+                         true /* writable */, kSource,
+                         true /* supports_notify_tag */, kOpenedFilesLimit,
+                         fake_watcher_);
 
   scoped_ptr<RegistryInterface::RestoredFileSystems> restored_file_systems =
       registry_->RestoreFileSystems(kExtensionId);
@@ -137,6 +142,7 @@ TEST_F(FileSystemProviderRegistryTest, RestoreFileSystems) {
   EXPECT_EQ(kFileSystemId, restored_file_system.options.file_system_id);
   EXPECT_EQ(kDisplayName, restored_file_system.options.display_name);
   EXPECT_TRUE(restored_file_system.options.writable);
+  EXPECT_EQ(kSource, restored_file_system.options.source);
   EXPECT_TRUE(restored_file_system.options.supports_notify_tag);
   EXPECT_EQ(kOpenedFilesLimit, restored_file_system.options.opened_files_limit);
 
@@ -153,6 +159,7 @@ TEST_F(FileSystemProviderRegistryTest, RestoreFileSystems) {
 TEST_F(FileSystemProviderRegistryTest, RememberFileSystem) {
   MountOptions options(kFileSystemId, kDisplayName);
   options.writable = true;
+  options.source = kSource;
   options.supports_notify_tag = true;
   options.opened_files_limit = kOpenedFilesLimit;
 
@@ -199,6 +206,11 @@ TEST_F(FileSystemProviderRegistryTest, RememberFileSystem) {
       file_system->GetBooleanWithoutPathExpansion(kPrefKeyWritable, &writable));
   EXPECT_TRUE(writable);
 
+  std::string source_as_string;
+  EXPECT_TRUE(file_system->GetStringWithoutPathExpansion(kPrefKeySource,
+                                                         &source_as_string));
+  EXPECT_EQ("network", source_as_string);
+
   bool supports_notify_tag = false;
   EXPECT_TRUE(file_system->GetBooleanWithoutPathExpansion(
       kPrefKeySupportsNotifyTag, &supports_notify_tag));
@@ -248,8 +260,9 @@ TEST_F(FileSystemProviderRegistryTest, RememberFileSystem) {
 TEST_F(FileSystemProviderRegistryTest, ForgetFileSystem) {
   // Create a fake file systems in the preferences.
   RememberFakeFileSystem(profile_, kExtensionId, kFileSystemId, kDisplayName,
-                         true /* writable */, true /* supports_notify_tag */,
-                         kOpenedFilesLimit, fake_watcher_);
+                         true /* writable */, kSource,
+                         true /* supports_notify_tag */, kOpenedFilesLimit,
+                         fake_watcher_);
 
   registry_->ForgetFileSystem(kExtensionId, kFileSystemId);
 
@@ -316,5 +329,28 @@ TEST_F(FileSystemProviderRegistryTest, UpdateWatcherTag) {
   EXPECT_EQ(fake_watcher_.last_tag, last_tag);
 }
 
+TEST_F(FileSystemProviderRegistryTest, SourceToString) {
+  {
+    Source result = SOURCE_UNKNOWN;
+    EXPECT_TRUE(StringToSource(SourceToString(SOURCE_FILE), &result));
+    EXPECT_EQ(SOURCE_FILE, result);
+  }
+  {
+    Source result = SOURCE_UNKNOWN;
+    EXPECT_TRUE(StringToSource(SourceToString(SOURCE_DEVICE), &result));
+    EXPECT_EQ(SOURCE_DEVICE, result);
+  }
+  {
+    Source result = SOURCE_UNKNOWN;
+    EXPECT_TRUE(StringToSource(SourceToString(SOURCE_NETWORK), &result));
+    EXPECT_EQ(SOURCE_NETWORK, result);
+  }
+  {
+    Source result = SOURCE_FILE;
+    EXPECT_TRUE(StringToSource(SourceToString(SOURCE_UNKNOWN), &result));
+    EXPECT_EQ(SOURCE_UNKNOWN, result);
+  }
+}
+
 }  // namespace file_system_provider
 }  // namespace chromeos
diff --git a/chrome/common/extensions/api/file_manager_private.idl b/chrome/common/extensions/api/file_manager_private.idl
index 68fc345..be6cd53 100644
--- a/chrome/common/extensions/api/file_manager_private.idl
+++ b/chrome/common/extensions/api/file_manager_private.idl
@@ -173,6 +173,20 @@ enum EntryTagVisibility {
   public
 };
 
+// Source of the volume data.
+enum VolumeSource {
+  // Represents a mounted file. In most cases, simply an archive.
+  file,
+
+  // Representing a device, eg. an MTP device. Also, used for Downloads as it's
+  // containing files stored on the Chrome OS device.
+  device,
+
+  // Used for volumes which contain files on a remote machine, eg. Drive or
+  // cloud services implemented via the File System Provider API.
+  network
+};
+
 // A file task represents an action that the file manager can perform over the
 // currently selected files. See
 // chrome/browser/chromeos/extensions/file_manager/file_tasks.h for details
@@ -280,12 +294,15 @@ dictionary VolumeMetadata {
   // ID of the disk volume.
   DOMString volumeId;
 
-  // Id the provided file system (for proviided file systems).
+  // Id the provided file system (for provided file systems).
   DOMString? fileSystemId;
 
   // Extension providing this volume (for provided file systems).
   DOMString? extensionId;
 
+  // Source of the volume data.
+  VolumeSource? volumeSource;
+
   // Label of the volume (if available).
   DOMString? volumeLabel;
 
diff --git a/chrome/common/extensions/api/file_system_provider.idl b/chrome/common/extensions/api/file_system_provider.idl
index 2854ae8..0b58961 100644
--- a/chrome/common/extensions/api/file_system_provider.idl
+++ b/chrome/common/extensions/api/file_system_provider.idl
@@ -41,6 +41,22 @@ namespace fileSystemProvider {
     DELETED
   };
 
+  // Source of the file system data.
+  enum FileSystemSource {
+    // The file system is handling a file, eg. an archive file obtained via the
+    // <code>OnLaunched</code> event and the <code>file_handlers</code> manifest
+    // entry.
+    FILE,
+
+    // The file system contents are fetched from an external device, such as a
+    // USB device, but not via <code>file_handlers</code>.
+    DEVICE,
+
+    // The file system is network based. The contents are obtained from another
+    // server or local network. Eg. cloud services.
+    NETWORK
+  };
+
   // Represents metadata of a file or a directory.
   dictionary EntryMetadata {
     // True if it is a directory.
@@ -109,6 +125,9 @@ namespace fileSystemProvider {
     // List of currently opened files.
     OpenedFile[] openedFiles;
 
+    // Source of the file system data.
+    FileSystemSource? source;
+
     // Whether the file system supports the <code>tag</code> field for observing
     // directories.
     [nodoc] boolean? supportsNotifyTag;
@@ -134,6 +153,9 @@ namespace fileSystemProvider {
     // or 0, then not limited.
     long? openedFilesLimit;
 
+    // Source of the file system data.
+    FileSystemSource? source;
+
     // Whether the file system supports the <code>tag</code> field for observed
     // directories. Required in order to enable the internal cache.
     [nodoc] boolean? supportsNotifyTag;
@@ -451,6 +473,9 @@ namespace fileSystemProvider {
     // must be descriptive but doesn't have to be unique. The <code>fileSystemId
     // </code> must not be an empty string.
     //
+    // Depending on the type of the file system being mounted, the <code>source
+    // </code> option must be set appropriately.
+    //
     // In case of an error, <code>chrome.runtime.lastError</code> will be set
     // will a corresponding error code.
     static void mount(MountOptions options,
diff --git a/chrome/test/data/extensions/api_test/file_browser/mount_test/test.js b/chrome/test/data/extensions/api_test/file_browser/mount_test/test.js
index ff09363..459a280 100644
--- a/chrome/test/data/extensions/api_test/file_browser/mount_test/test.js
+++ b/chrome/test/data/extensions/api_test/file_browser/mount_test/test.js
@@ -7,6 +7,7 @@ var expectedVolume1 = {
   volumeId: 'removable:mount_path1',
   volumeLabel: 'mount_path1',
   sourcePath: 'device_path1',
+  volumeSource: 'device',
   volumeType: 'removable',
   deviceType: 'usb',
   devicePath: 'system_path_prefix1',
@@ -20,6 +21,7 @@ var expectedVolume2 = {
   volumeId: 'removable:mount_path2',
   volumeLabel: 'mount_path2',
   sourcePath: 'device_path2',
+  volumeSource: 'device',
   volumeType: 'removable',
   deviceType: 'mobile',
   devicePath: 'system_path_prefix2',
@@ -33,6 +35,7 @@ var expectedVolume3 = {
   volumeId: 'removable:mount_path3',
   volumeLabel: 'mount_path3',
   sourcePath: 'device_path3',
+  volumeSource: 'device',
   volumeType: 'removable',
   deviceType: 'optical',
   devicePath: 'system_path_prefix3',
@@ -45,6 +48,7 @@ var expectedVolume3 = {
 var expectedDownloadsVolume = {
   volumeId: /^downloads:Downloads[^\/]*$/,
   volumeLabel: '',
+  volumeSource: 'device',
   volumeType: 'downloads',
   isReadOnly: false,
   hasMedia: false,
@@ -55,6 +59,7 @@ var expectedDriveVolume = {
   volumeId: /^drive:drive[^\/]*$/,
   volumeLabel: '',
   sourcePath: /^\/special\/drive[^\/]*$/,
+  volumeSource: 'network',
   volumeType: 'drive',
   isReadOnly: false,
   hasMedia: false,
@@ -65,6 +70,7 @@ var expectedArchiveVolume = {
   volumeId: 'archive:archive_mount_path',
   volumeLabel: 'archive_mount_path',
   sourcePath: /removable\/mount_path3\/archive.zip$/,
+  volumeSource: 'file',
   volumeType: 'archive',
   isReadOnly: true,
   hasMedia: false,
diff --git a/chrome/test/data/extensions/api_test/file_system_provider/get_all/test.js b/chrome/test/data/extensions/api_test/file_system_provider/get_all/test.js
index a0fa062..993925f 100644
--- a/chrome/test/data/extensions/api_test/file_system_provider/get_all/test.js
+++ b/chrome/test/data/extensions/api_test/file_system_provider/get_all/test.js
@@ -86,6 +86,8 @@ function runTests() {
                                     fileSystems[0].displayName);
                                 chrome.test.assertTrue(
                                     fileSystems[0].writable);
+                                chrome.test.assertEq(
+                                    'NETWORK', fileSystems[0].source);
                                 chrome.test.assertEq(2,
                                     fileSystems[0].openedFilesLimit);
                               }));
@@ -100,6 +102,8 @@ function runTests() {
                                     test_util.FILE_SYSTEM_NAME,
                                     fileSystem.displayName);
                                 chrome.test.assertTrue(fileSystem.writable);
+                                chrome.test.assertEq(
+                                    'NETWORK', fileSystem.source);
                                 chrome.test.assertEq(2,
                                     fileSystem.openedFilesLimit);
                                 }));
@@ -113,7 +117,7 @@ function runTests() {
                 function(error) {
                   chrome.test.fail(error.name);
                 });
-          }), {writable: true, openedFilesLimit: 2});
+          }), {writable: true, openedFilesLimit: 2, source: 'NETWORK'});
     },
 
     // Verifies that after unmounting, the file system is not available in
diff --git a/chrome/test/data/extensions/api_test/file_system_provider/mount/test.js b/chrome/test/data/extensions/api_test/file_system_provider/mount/test.js
index 83e2c37..022d384 100644
--- a/chrome/test/data/extensions/api_test/file_system_provider/mount/test.js
+++ b/chrome/test/data/extensions/api_test/file_system_provider/mount/test.js
@@ -65,7 +65,11 @@ chrome.test.runTests([
   function successfulMount() {
     var fileSystemId = 'caramel-candy';
     chrome.fileSystemProvider.mount(
-        {fileSystemId: fileSystemId, displayName: 'caramel-candy.zip'},
+        {
+          fileSystemId: fileSystemId,
+          displayName: 'caramel-candy.zip',
+          source: 'FILE'
+        },
         chrome.test.callbackPass(function() {
           chrome.fileManagerPrivate.getVolumeMetadataList(function(volumeList) {
             var volumeInfo;