offline_items_collection : Added helper class to determine progress

components/offline_items_collection/core/offline_item.h

Index: components/offline_items_collection/core/offline_item.h
diff --git a/components/offline_items_collection/core/offline_item.h b/components/offline_items_collection/core/offline_item.h
index c588253f1f447f55b205f9a8071695a17e795ac9..e55a41b85870254fb2f1308590fe19af5c2ad4c0 100644
--- a/components/offline_items_collection/core/offline_item.h
+++ b/components/offline_items_collection/core/offline_item.h
@@ -9,6 +9,7 @@
 
 #include "base/time/time.h"
 #include "components/offline_items_collection/core/offline_item_filter.h"
+#include "components/offline_items_collection/core/offline_item_progress_unit.h"
 #include "components/offline_items_collection/core/offline_item_state.h"
 #include "ui/gfx/image/image.h"
 #include "url/gurl.h"
@@ -46,6 +47,25 @@ struct ContentId {
 //
 // A new feature should expose these OfflineItems via an OfflineContentProvider.
 struct OfflineItem {
+  // This struct holds the essential pieces of information to compute the
+  // download progress percentage for an offline item to display in the UI.

[David Trainor- moved to gerrit, 2017/05/03 22:06:32]

remove "percentage"

[shaktisahu, 2017/05/05 02:09:37]

Done.

+  struct Progress {
+    Progress();
+    Progress(const Progress& other);
+    ~Progress();
+
+    bool operator==(const Progress& progress) const;
+
+    // Current value of the download progress.
+    int64_t value;
+
+    // The maximum value of the download progress. -1 indicates indeterminate.

[David Trainor- moved to gerrit, 2017/05/03 22:06:32]

Can this just be a base::Optional?  If it's not there we will treat it as
indeterminate.

[shaktisahu, 2017/05/05 02:09:37]

Done.

+    int64_t max;
+
+    // The unit of progress to be displayed in the UI.
+    OfflineItemProgressUnit unit;
+  };
+
   OfflineItem();
   OfflineItem(const OfflineItem& other);
   explicit OfflineItem(const ContentId& id);
@@ -122,11 +142,8 @@ struct OfflineItem {
   // if |state| is COMPLETE.
   int64_t received_bytes;
 
-  // How complete (from 0 to 100) the offlining process is for this item.  -1
-  // represents that progress cannot be determined for this item and an
-  // indeterminate progress bar should be used.  This field is not used if
-  // |state| is COMPLETE.
-  int percent_completed;
+  // Represents the current progress of this item.

[David Trainor- moved to gerrit, 2017/05/03 22:06:32]

Keep some of the information here.  The field is not used if |state| is
COMPLETE.

[shaktisahu, 2017/05/05 02:09:37]

Done.

+  Progress progress;
 
   // The estimated time remaining for the download in milliseconds.  -1
   // represents an unknown time remaining.  This field is not used if |state| is