Storage manager simply shows |real remaining size|.
Files app shows the remaining size using following math.
|real remaining size| + |evictable cache size| - 512MB.

|evictable cache size| is added because users will be able to use the space by automatic cache eviction.
512MB is subtracted because 512MB is the minimum space. If the real remaining size is 800MB, the actual margin users can use is (800 - 512) = 288MB.

By introducing Storage manager, it becomes confusing.
I think following options are better now.
1) In Files app, simply show |real remaining size|. It is same as "Available" in Storage manager.
2) In Files app, show |real remaining size| + |evictable cache size|. It is basically same as "Avalable" + "Offline files" in Storage manager.

Hiro, WDYT?

filled same issue here https://buganizer.corp.google.com/issues/31042070

Consistency is a good thing. Let's do this: 

1. Change the copy in Files app from xxxGB left to Available
2. Use the same math in Files app as we do in storage management for available space

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e23227790211a07cbb31d711a2a52e313f8fc0d1

commit e23227790211a07cbb31d711a2a52e313f8fc0d1
Author: fukino <fukino@chromium.org>
Date: Thu Aug 25 09:17:10 2016

Make chrome.fileManagerPrivate.getSizeStat return actual available space for Downloads.

getSizeStat() for Downloads used to return
|actual available space| + |evictable Drive cache| - 512MB.
To be consistent with Storage manager (chrome://settings/storage), getSizeStat()
should simplly return |actual available size|.

BUG= 640504 
TEST=manually compared the avaiable space in Files app and Storage manager.

Review-Url: https://codereview.chromium.org/2274003004
Cr-Commit-Position: refs/heads/master@{#414371}

[modify] https://crrev.com/e23227790211a07cbb31d711a2a52e313f8fc0d1/chrome/app/chromeos_strings.grdp
[modify] https://crrev.com/e23227790211a07cbb31d711a2a52e313f8fc0d1/chrome/browser/chromeos/extensions/file_manager/private_api_file_system.cc
[modify] https://crrev.com/e23227790211a07cbb31d711a2a52e313f8fc0d1/chrome/browser/chromeos/extensions/file_manager/private_api_file_system.h

Thanks Hiro, Jonny!
The change described in c#5 has landed.
Closing...

Now storage space is same in Files app and Storage manager.

But its not consistent with settings-> android preference-> storage.
Verified on Chrome:54.0.2840.10/Chromeos:8743.8.0.

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	Screenshot 2016-09-02 at 1.59.05 PM.png 290 KB View Download

Is this going into M53?
They don't match for me in latest 8530.84.0

Deleted: Screenshot 2016-09-13 at 3.55.46 PM.png 74.7 KB

	Screenshot 2016-09-13 at 3.55.46 PM.png 74.7 KB View Download

I suppose it's not going to be merged to M53 as it is P2.
mitsuji@, could you double check? Should we ask a merge for M53?

Hmm, that's a shame, I thought this change was merged into M53. At this point it's a bit late IMO, can we treat this as a bug fix in M54? 

M54 already has the fix. (The fix landed on the M54 branch cut day)
Let me keep this as Fixed and M-54 label for this.

Verified on build 8861.0.0