Chrome Version: M66
OS: Android

What steps will reproduce the problem?
(1) Use a very out-of-date version of Chrome for Android, more than 2 milestones behind.
(2) Have less than X MB storage available on your device.
(3) Get a prompt to update Chrome
(4) Tap the menu-icon and select the update-Chrome action
(5) When entering the Play Store try to update Chrome

What is the expected result?
Chrome is updated.

What happens instead?
If the available disk space is less than X MB, the update fails.

What can we do to improve it?
Given:
* X - Minimum available disk space for upgrade.
* Y - Currently available storage space on the device.
* Z - The current size of the Chrome cache.
We could try the following approach:
###
ready_to_proceed = True
if Y < X and Y+Z >= X:
  # Set ready_to_proceed to False if the deleted data is less than |minimum_cleanup_size|, else True.
  ready_to_proceed = clear_chrome_cache(minimum_cleanup_size = X-Z)

if ready_to_proceed:
  proceed_to_play_store()
else:
  inform_user_of_storage_issue()
###

Depending how much we trust X, we could even potentially skip taking the user to the Play Store and instead telling them that we foresee possible issues with updating the application.

The value for X should definitely be configurable.

If we see that clearing the cache takes a long time, we should consider showing a spinner, or something along those lines, while we tell the user that we're preparing their device for the update.
 

Chrome Version: M66
OS: Android

What steps will reproduce the problem?
(1) Use a very out-of-date version of Chrome for Android, more than 2 milestones behind.
(2) Have less than X MB storage available on your device.
(3) Get a prompt to update Chrome
(4) Tap the menu-icon and select the update-Chrome action
(5) When entering the Play Store try to update Chrome

What is the expected result?
Chrome is updated.

What happens instead?
If the available disk space is less than X MB, the update fails.

What can we do to improve it?
Given:
* X - Minimum available disk space for upgrade.
* Y - Currently available storage space on the device.
* Z - The current size of the Chrome cache.
We could try the following approach:
###
ready_to_proceed = True
if Y < X and Y+Z >= X:
  # Set ready_to_proceed to False if the deleted data is less than |minimum_cleanup_size|, else True.
  ready_to_proceed = clear_chrome_cache(minimum_cleanup_size = X-Z)

if ready_to_proceed:
  proceed_to_play_store()
else:
  inform_user_of_storage_issue()
###

Depending how much we trust X, we could even potentially skip taking the user to the Play Store and instead telling them that we foresee possible issues with updating the application.

The value for X should definitely be configurable.

If we see that clearing the cache takes a long time, we should consider showing a spinner, or something along those lines, while we tell the user that we're preparing their device for the update.

We should also investigate whether this negatively impacts future browser performance, since we lose the cached data.