Checked the issue on reported chrome version 64.0.3282.119 and on the latest dev 66.0.3342.0 using Ubuntu 14.04 with the below mentioned steps.
1. Launched Chrome
2. Clicked on secure chip(on the top left bar of omni box)
3. Clicked on Cookies(in use)
We observed the buttons "Block, Remove and Done". Attaching the screenshot for reference.

Note: Non availability of 13 inch or smaller screen we used HP Elite Book(14 inch screen), we decreased the screen resolution of 14 inch(with 3840*2160) to 1024*768 which is lesser than a usual recommended 13 inch(1280*800) display. We have assumed that changing the screen resolution would bring us that environment to test.

@Reporter: Could you please confirm whether the above mentioned steps could reproduce the issue or only using a 13 inch or lesser screen would do. Any further inputs from your end may help us to triage the issue in a better way.

Thanks!

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Yes, I still have the same issue after following the steps above (these steps are the same as in my original report).

Output from xrandr:

Screen 0: minimum 8 x 8, current 1366 x 768, maximum 32767 x 32767
eDP1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 293mm x 164mm
   1366x768      60.01*+
   1360x768      59.80    59.96  
   1280x720      60.00  
   1024x768      60.00  
   1024x576      60.00  
   960x540       60.00  
   800x600       60.32    56.25  
   864x486       60.00  
   640x480       59.94  
   720x405       60.00  
   680x384       60.00  
   640x360       60.00  
HDMI1 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

Thank you for providing more feedback. Adding the requester to the cc list.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Graphics part of inxi -Fxz:

Graphics:
	Card: Intel Broadwell-U Integrated Graphics bus-ID: 00:02.0
	Display Server: X.Org 1.18.4 drivers: intel (unloaded: fbdev,vesa) 
	Resolution: 1366x768@60.01hz
	GLX Renderer: Mesa DRI Intel HD Graphics 5500 (Broadwell GT2)
	GLX Version: 3.0 Mesa 17.0.7 Direct Rendering: Yes

I think the solution to this would be to make all dialog boxes scrollable.

rizwaanb10@ Thanks for the update.

Tested this issue on the latest Stable 67.0.3396.62 on Ubuntu 17.10 and unable to reproduce the issue
As Linux Mint 18.3 13 inch or smaller screen is unavailable at TE end to test this issue, adding 'TE-Hardware-Dependency' label for further help in triaging the issue.

Thanks..

Its actually very easy to reproduce this issue, on a wide screen monitor, simply resize the window until the buttons for removing cookies and closing the "Cookies in use" dialog are out of view. You'll notice that there is no way to access them.

susan.boorgula@ See my comment above.

See attached screenshot.

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	Screenshot from 2018-05-31 13-15-06.png 435 KB View Download