Propagate the read_only_hardware flag of volumes to js.

chrome/browser/chromeos/file_manager/volume_manager.h

Index: chrome/browser/chromeos/file_manager/volume_manager.h
diff --git a/chrome/browser/chromeos/file_manager/volume_manager.h b/chrome/browser/chromeos/file_manager/volume_manager.h
index cc4ae549c50a89f43747aa34f45edff7cc55dc43..a4615cda3648329a8f71f2313a370074c126b2ba 100644
--- a/chrome/browser/chromeos/file_manager/volume_manager.h
+++ b/chrome/browser/chromeos/file_manager/volume_manager.h
@@ -116,7 +116,16 @@ class Volume : public base::SupportsWeakPtr<Volume> {
   }
   const std::string& volume_label() const { return volume_label_; }
   bool is_parent() const { return is_parent_; }
+  // Whether the applications can write to the volume. True if not writable.
+  // For example, when write access to external storage is restricted by the
+  // policy (ExternalStorageReadOnly), is_read_only() will be true even when
+  // is_read_only_hardware() is false.
   bool is_read_only() const { return is_read_only_; }
+  // Whether the device is write-protected by hardware. This field is valid
+  // only when device_type is VOLUME_TYPE_REMOVABLE_DISK_PARTITION and
+  // source is SOURCE_DEVICE.
+  // When this value is true, is_read_only() is also true.
+  bool is_read_only_hardware() const { return is_read_only_hardware_; }

[fukino, 2016/10/27 05:27:34]

optional nit: is_read_only_device might be more consistent naming with
SOURCE_DEVICE?

[yamaguchi, 2016/10/27 07:32:54]

In Disk class, "hardware" was adopted for the field name to emphasize the
difference between mount option (given by software) and the device itself.
Regarding the new fields in this change, I agree that it'd be better to have
relevant name to either the VOLUME_TYPE_REMOVABLE_DISK_PARTITION or
SOURCE_DEVICE.

   bool has_media() const { return has_media_; }
   bool configurable() const { return configurable_; }
   bool watchable() const { return watchable_; }
@@ -175,9 +184,13 @@ class Volume : public base::SupportsWeakPtr<Volume> {
   // Is the device is a parent device (i.e. sdb rather than sdb1).
   bool is_parent_;
 
-  // True if the volume is read only.
+  // True if the volume is not writable by applications.
   bool is_read_only_;
 
+  // True if the volume is made read_only due to its hardware.
+  // This implies is_read_only_.
+  bool is_read_only_hardware_;
+
   // True if the volume contains media.
   bool has_media_;