This is issue is first seen on M46 - 46.0.2477.0 , Below link gives in details of the number of instances in which the crash has occurred for associated builds:
https://goto.google.com/emxsq

1. Overall 4 crash instances are seen on latest stable M49-49.0.2623.8, 5 crash instances on latest Beta M50-50.0.2661.26 and 2 crash instances on latest Dev M50-50.0.2661.18.
2.Last crash is observed on M51-51.0.2673.0 with 3 instances
3. Crash is observed on Windows and Mac OS as per below link
https://goto.google.com/kmchi

Note: This crash was seen earlier version of chrome and got closed recently (bug 549502), But still crash instances are seen on latest builds so filing new one as per fracas dashboard.

Used code search for the file "fullscreen_controller.cc" and suspecting the below change
Review URL: https://codereview.chromium.org/836933005
sriram@: Observed some changes on this file from your end. Could you please check if this is caused with respect to your change, if not please help us in reassign the issue to the right owner. 

Thanks!

Users experienced this crash on the following builds:

Mac Beta 50.0.2661.26 - 5 reports, 3 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Users experienced this crash on the following builds:

Mac Canary 52.0.2708.0 -  0.33 CPM, 1 reports, 1 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Users experienced this crash on the following builds:

Mac Canary 53.0.2748.0 -  0.28 CPM, 1 reports, 1 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Moving this nonessential bug to the next milestone.

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

Users experienced this crash on the following builds:

Mac Canary 53.0.2754.0 -  0.31 CPM, 2 reports, 2 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Users experienced this crash on the following builds:

Mac Dev 53.0.2756.0 -  0.22 CPM, 1 reports, 1 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Unassigning myself as I am not currently working in this component and so it is correctly triaged. 

Users experienced this crash on the following builds:

Mac Beta 52.0.2743.33 -  0.20 CPM, 2 reports, 2 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Users experienced this crash on the following builds:

Mac Stable 51.0.2704.106 -  0.05 CPM, 3 reports, 3 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Users experienced this crash on the following builds:

Mac Canary 54.0.2786.0 -  2.66 CPM, 2 reports, 1 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

This issue has been moved once and is lower than Pri-1. Removing the milestone.

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

Users experienced this crash on the following builds:

Mac Canary 55.0.2848.0 -  2.82 CPM, 2 reports, 2 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Users experienced this crash on the following builds:

Mac Canary 56.0.2885.0 -  1.36 CPM, 1 reports, 1 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Users experienced this crash on the following builds:

Mac Canary 57.0.2926.0 -  0.92 CPM, 1 reports, 1 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Better stack with symbols:

Thread 0 CRASHED [EXC_BAD_ACCESS / EXC_I386_GPFLT @ 0x000000010c91ca3a ] MAGIC SIGNATURE THREAD

0x000000010c91ca3a	(Google Chrome Framework -fullscreen_controller.cc:316 )	FullscreenController::NotifyTabExclusiveAccessLost()
0x000000010c91c7d3	(Google Chrome Framework -fullscreen_controller.cc:251 )	FullscreenController::WindowFullscreenStateChanged()
0x000000010c8fefe8	(Google Chrome Framework -browser.cc:794 )	Browser::WindowFullscreenStateChanged()
0x000000010ca9b9e6	(Google Chrome Framework -browser_window_controller_private.mm:722 )	-[BrowserWindowController(Private) windowDidExitFullScreen:]
0x00007fffd08ab59b	(CoreFoundation + 0x0009d59b )	__CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__
0x00007fffd08ab49a	(CoreFoundation + 0x0009d49a )	_CFXRegistrationPost
0x00007fffd08ab201	(CoreFoundation + 0x0009d201 )	___CFXNotificationPost_block_invoke
0x00007fffd0868902	(CoreFoundation + 0x0005a902 )	-[_CFXNotificationRegistrar find:object:observer:enumerator:]
0x00007fffd086793b	(CoreFoundation + 0x0005993b )	_CFXNotificationPost
0x00007fffd22770e2	(Foundation + 0x000070e2 )	-[NSNotificationCenter postNotificationName:object:userInfo:]
0x00007fffce73d275	(AppKit + 0x0035c275 )	-[NSWindow _didExitFullScreen:]
0x00007fffcee647d6	(AppKit + 0x00a837d6 )	__123-[_NSWindowFullScreenTransition _performExitFullScreenModeForWindow:windowController:options:customWindows:doKitAnimation:]_block_invoke_2
0x00007fffcee6455c	(AppKit + 0x00a8355c )	__123-[_NSWindowFullScreenTransition _performExitFullScreenModeForWindow:windowController:options:customWindows:doKitAnimation:]_block_invoke
0x00007fffce92438b	(AppKit + 0x0054338b )	__NSFullScreenDockConnectionSendExitForTransition_block_invoke
0x00007fffe5d5ad84	(libxpc.dylib + 0x00009d84 )	_xpc_connection_reply_callout
0x00007fffe5d5ad12	(libxpc.dylib + 0x00009d12 )	_xpc_connection_call_reply
0x00007fffe5ac7127	(libdispatch.dylib + 0x00002127 )	_dispatch_client_callout
0x00007fffe5ad4bb2	(libdispatch.dylib + 0x0000fbb2 )	_dispatch_main_queue_callback_4CF
0x00007fffd08d4be8	(CoreFoundation + 0x000c6be8 )	__CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__
0x00007fffd089600c	(CoreFoundation + 0x0008800c )	__CFRunLoopRun
0x00007fffd0895513	(CoreFoundation + 0x00087513 )	CFRunLoopRunSpecific
0x00007fffcfe262ab	(HIToolbox + 0x000312ab )	RunCurrentEventLoopInMode
0x00007fffcfe260e0	(HIToolbox + 0x000310e0 )	ReceiveNextEventCommon
0x00007fffcfe25f15	(HIToolbox + 0x00030f15 )	_BlockUntilNextEventMatchingListInModeWithFilter
0x00007fffce4286cc	(AppKit + 0x000476cc )	_DPSNextEvent
0x00007fffceb9f82f	(AppKit + 0x007be82f )	-[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:]
0x000000010a00000f	(Google Chrome Framework -chrome_browser_application_mac.mm:187 )	__71-[BrowserCrApplication nextEventMatchingMask:untilDate:inMode:dequeue:]_block_invoke
0x000000010a448879	(Google Chrome Framework + 0x01997879 )	base::mac::CallWithEHFrame(void () block_pointer)
0x0000000109ffff48	(Google Chrome Framework -chrome_browser_application_mac.mm:186 )	-[BrowserCrApplication nextEventMatchingMask:untilDate:inMode:dequeue:]
0x00007fffce41d06c	(AppKit + 0x0003c06c )	-[NSApplication run]
0x000000010a45844d	(Google Chrome Framework -message_pump_mac.mm:637 )	base::MessagePumpNSApplication::DoRun(base::MessagePump::Delegate*)
0x000000010a457acb	(Google Chrome Framework -message_pump_mac.mm:210 )	base::MessagePumpCFRunLoopBase::Run(base::MessagePump::Delegate*)
0x000000010a4763f2	(Google Chrome Framework -run_loop.cc:37 )	base::RunLoop::Run()
0x000000010a005a38	(Google Chrome Framework -chrome_browser_main.cc:1987 )	ChromeBrowserMainParts::MainMessageLoopRun(int*)
0x00000001097f43d3	(Google Chrome Framework -browser_main_loop.cc:1171 )	content::BrowserMainLoop::RunMainMessageLoopParts()
0x00000001097f7091	(Google Chrome Framework -browser_main_runner.cc:141 )	content::BrowserMainRunnerImpl::Run()
0x00000001097eff7b	(Google Chrome Framework -browser_main.cc:46 )	content::BrowserMain(content::MainFunctionParams const&)
0x0000000109fbd6df	(Google Chrome Framework -content_main_runner.cc:793 )	content::ContentMainRunnerImpl::Run()
0x0000000109fbc9a5	(Google Chrome Framework -content_main.cc:20 )	content::ContentMain(content::ContentMainParams const&)
0x0000000108ab3e7a	(Google Chrome Framework -chrome_main.cc:112 )	ChromeMain
0x0000000104901d99	(Google Chrome Canary + 0x00000d99 )	
0x00007fffe5afd254	(libdyld.dylib + 0x00005254 )	start
0x00007fffe5afd254	(libdyld.dylib + 0x00005254 )	start

Users experienced this crash on the following builds:

Mac Canary 58.0.2988.0 -  0.41 CPM, 1 reports, 1 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

 Issue 687830  has been merged into this issue.

The reporter in  issue 687830  has repro steps.

Users experienced this crash on the following builds:

Mac Canary 59.0.3037.0 -  0.77 CPM, 1 reports, 1 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Users experienced this crash on the following builds:

Mac Canary 60.0.3084.0 -  1.16 CPM, 1 reports, 1 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Users experienced this crash on the following builds:

Mac Canary 61.0.3117.0 -  0.35 CPM, 1 reports, 1 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Users experienced this crash on the following builds:

Mac Beta 62.0.3202.29 -  0.05 CPM, 3 reports, 3 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Users experienced this crash on the following builds:

Mac Canary 63.0.3234.0 -  0.40 CPM, 1 reports, 1 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Users experienced this crash on the following builds:

Mac Canary 64.0.3251.0 -  0.43 CPM, 1 reports, 1 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Users experienced this crash on the following builds:

Mac Dev 65.0.3322.3 -  0.13 CPM, 2 reports, 2 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Users experienced this crash on the following builds:

Mac Canary 66.0.3345.0 -  0.78 CPM, 1 reports, 1 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Users experienced this crash on the following builds:

Mac Beta 65.0.3325.124 -  0.10 CPM, 4 reports, 4 clients (signature FullscreenController::NotifyTabExclusiveAccessLost)

If this update was incorrect, please add "Fracas-Wrong" label to prevent future updates.

- Go/Fracas

Archiving old bugs that haven't been actively assigned in over 180 days.

If you feel this issue should still be addressed, feel free to reopen it or to file a new issue. Thanks!