When copying out of the omnibox in a mac_views_browser=1 build:

[80462:1295:0421/150130:FATAL:textfield.cc(1633)] Check failed: kNoCommand == scheduled_edit_command_ (0 vs. 11056)
0   libbase.dylib                       0x000000010ff8c7cf _ZN4base5debug10StackTraceC2Ev + 47
1   libbase.dylib                       0x000000010ff8c973 _ZN4base5debug10StackTraceC1Ev + 35
2   libbase.dylib                       0x0000000110019e60 _ZN7logging10LogMessageD2Ev + 80
3   libbase.dylib                       0x0000000110017793 _ZN7logging10LogMessageD1Ev + 35
4   libviews.dylib                      0x0000000121388122 _ZN5views9Textfield29SetEditCommandForNextKeyEventEi + 194
5   libviews.dylib                      0x0000000121388192 _ZThn448_N5views9Textfield29SetEditCommandForNextKeyEventEi + 50
6   libviews.dylib                      0x0000000121289a4b -[BridgedContentView handleAction:keyCode:domCode:eventFlags:] + 283
7   libviews.dylib                      0x000000012128a1e0 -[BridgedContentView copy:] + 352
8   libsystem_trace.dylib               0x00007fff8d3ed07a _os_activity_initiate + 75
9   AppKit                              0x00007fff9856ce89 -[NSApplication sendAction:to:from:] + 460
10  libchrome_main_dll.dylib            0x0000000104ab778d -[BrowserCrApplication sendAction:to:from:] + 1085
11  AppKit                              0x00007fff9856cc23 -[NSMenuItem _corePerformAction] + 336
12  AppKit                              0x00007fff9856c983 -[NSCarbonMenuImpl performActionWithHighlightingForItemAtIndex:] + 114
13  libsystem_trace.dylib               0x00007fff8d3ed07a _os_activity_initiate + 75
14  AppKit                              0x00007fff9856b871 -[NSMenu performKeyEquivalent:] + 357
15  AppKit                              0x00007fff9856aa15 -[NSApplication _handleKeyEquivalent:] + 920
16  AppKit                              0x00007fff98491202 -[NSApplication sendEvent:] + 4274
17  libchrome_main_dll.dylib            0x0000000104ab7a83 __34-[BrowserCrApplication sendEvent:]_block_invoke + 259
18  libbase.dylib                       0x000000011001d67a _ZN4base3mac15CallWithEHFrameEU13block_pointerFvvE + 10
19  libchrome_main_dll.dylib            0x0000000104ab795d -[BrowserCrApplication sendEvent:] + 109
20  AppKit                              0x00007fff982f7ef6 -[NSApplication run] + 796
21  libbase.dylib                       0x000000010ff38368 _ZN4base24MessagePumpNSApplication5DoRunEPNS_11MessagePump8DelegateE + 312
22  libbase.dylib                       0x000000010ff36c5d _ZN4base24MessagePumpCFRunLoopBase3RunEPNS_11MessagePump8DelegateE + 125
23  libbase.dylib                       0x0000000110061b5a _ZN4base11MessageLoop10RunHandlerEv + 298
24  libbase.dylib                       0x000000011010b5d5 _ZN4base7RunLoop3RunEv + 85
25  libchrome_main_dll.dylib            0x0000000104ac2c60 _ZN22ChromeBrowserMainParts18MainMessageLoopRunEPi + 400
26  libcontent.dylib                    0x00000001133ad40a _ZN7content15BrowserMainLoop23RunMainMessageLoopPartsEv + 410
27  libcontent.dylib                    0x00000001133b7551 _ZN7content21BrowserMainRunnerImpl3RunEv + 481
28  libcontent.dylib                    0x00000001133a187b _ZN7content11BrowserMainERKNS_18MainFunctionParamsE + 635
29  libcontent.dylib                    0x000000011305c347 _ZN7content23RunNamedProcessTypeMainERKNSt3__112basic_stringIcNS0_11char_traitsIcEENS0_9allocatorIcEEEERKNS_18MainFunctionParamsEPNS_19ContentMainDelegateE + 599
30  libcontent.dylib                    0x000000011305e312 _ZN7content21ContentMainRunnerImpl3RunEv + 626
31  libcontent.dylib                    0x000000011305b99d _ZN7content11ContentMainERKNS_17ContentMainParamsE + 349
32  libchrome_main_dll.dylib            0x000000010477e563 ChromeMain + 83
33  Chromium                            0x000000010450e0af main + 783
34  Chromium                            0x000000010450dd94 start + 52

Trace/BPT trap

I can't reproduce this reliably.