Chrome Version: 65.0.3294.0
OS: macOS 10.12.6

What steps will reproduce the problem?
(1) Go to https://chromium-review.googlesource.com/c/chromium/src/+/817515/5/content/app/content_main_runner.cc, select some text in the RHS of the code review, and try and copy it. Use Cmd+C, context-menu Copy, or Edit>Copy.
(2) Open TextEdit
(3) Try and paste the content
(4) System beep / nothing is copied
(5) Go to https://www.chromium.org, highlight some page text, and then copy it via any mechanism
(6) Switch back to TextEdit
(7) Paste works

What is the expected result?
Copy/paste should work everywhere.

What happens instead?
Copy/paste is broken on certain sites. In the STRs, it's the code review tool.

Please use labels and text to provide additional information.
Running `log stream` shows some interesting results:

At step (1) the following is seen:
2017-12-14 15:32:16.062832-0500 0x72b60b   Default     0x80000000000b7724   463    pboard: (CoreFoundation) [com.apple.CFPasteboard.remote] Installing local data provider: (uuid:63367949-1E9B-4D0C-84BB-D6E4A7F4780B gen: 1740 item: 789514 flavor: 'org.chromium.web-custom-data') for gen: 1740 index: 0 item: 789514
2017-12-14 15:32:16.063220-0500 0x72a886   Activity    0x80000000000b7725   12978  Google Chrome Canary: (CoreFoundation) SetData
2017-12-14 15:32:16.063294-0500 0x72b6ed   Default     0x80000000000b7724   498    useractivityd: [com.apple.useractivity.pasteboard-server] [PBOARD CONTROLLER] Got type update from client, gen: 1740, <private>
2017-12-14 15:32:16.113286-0500 0x72b754   Default     0x80000000000b7724   463    pboard: (UserActivity) [com.apple.useractivity.pasteboard-client] Sending pasteboard update to server: <private>
2017-12-14 15:32:16.113722-0500 0x72b6ed   Default     0x80000000000b7724   498    useractivityd: [com.apple.useractivity.pasteboard-server] [PBOARD CONTROLLER] Got type update from client, gen: 1740, <private>
2017-12-14 15:32:16.561062-0500 0x72b6ed   Default     0x0                  498    useractivityd: [com.apple.useractivity.main] PICKING: E1BC2E61-1FD8-4BD7-9844-B8AF31F43385/<private> as the current item-to-advertise.

But at step (5) this is seen:

2017-12-14 15:32:33.537527-0500 0x72b60b   Default     0x80000000000b7747   463    pboard: (CoreFoundation) [com.apple.CFPasteboard.remote] Installing local data provider: (uuid:0A51BFB0-A5E9-45C0-B89E-52B7F69D0D27 gen: 1741 item: 789514 flavor: 'public.html') for gen: 1741 index: 0 item: 789514
2017-12-14 15:32:33.538030-0500 0x72a886   Activity    0x80000000000b7748   12978  Google Chrome Canary: (CoreFoundation) SetData
2017-12-14 15:32:33.538068-0500 0x72b7c3   Default     0x80000000000b7747   498    useractivityd: [com.apple.useractivity.pasteboard-server] [PBOARD CONTROLLER] Got type update from client, gen: 1741, <private>
2017-12-14 15:32:33.538606-0500 0x72a886   Activity    0x80000000000b7749   12978  Google Chrome Canary: (CoreFoundation) PromiseData
2017-12-14 15:32:33.539082-0500 0x72b7e0   Default     0x80000000000b7749   463    pboard: (CoreFoundation) [com.apple.CFPasteboard.remote] Installing local data provider: (uuid:BF1876B0-54D5-4078-88C4-E87BD712B2E9 gen: 1741 item: 789514 flavor: 'public.utf8-plain-text') for gen: 1741 index: 0 item: 789514
2017-12-14 15:32:33.539482-0500 0x72a886   Activity    0x80000000000b774a   12978  Google Chrome Canary: (CoreFoundation) SetData
2017-12-14 15:32:33.539984-0500 0x72a886   Activity    0x80000000000b774b   12978  Google Chrome Canary: (CoreFoundation) PromiseData
2017-12-14 15:32:33.540383-0500 0x72b7e0   Default     0x80000000000b774b   463    pboard: (CoreFoundation) [com.apple.CFPasteboard.remote] Installing local data provider: (uuid:3E31583C-C6EE-4901-9743-AE9ED86DED2E gen: 1741 item: 789514 flavor: 'dyn.ah62d4rv4gu8y63n2nuuhg5pbsm4ca6dbsr4gnkduqf31k3pcr7u1e3basv61a3k') for gen: 1741 index: 0 item: 789514
2017-12-14 15:32:33.540729-0500 0x72a886   Activity    0x80000000000b774c   12978  Google Chrome Canary: (CoreFoundation) SetData
2017-12-14 15:32:33.590388-0500 0x72b7e0   Default     0x80000000000b7747   463    pboard: (UserActivity) [com.apple.useractivity.pasteboard-client] Sending pasteboard update to server: <private>
2017-12-14 15:32:33.590461-0500 0x72b7e0   Default     0x80000000000b7747   463    pboard: (UserActivity) [com.apple.useractivity.pasteboard-client] [Local Pasteboard] Adding alias: public.text for type: public.utf8-plain-text
2017-12-14 15:32:33.590934-0500 0x72b7c3   Default     0x80000000000b7747   498    useractivityd: [com.apple.useractivity.pasteboard-server] [PBOARD CONTROLLER] Got type update from client, gen: 1741, <private>
2017-12-14 15:32:33.737407-0500 0x72b746   Default     0x0                  498    useractivityd: [com.apple.useractivity.main] PICKING: 6D53E68E-91D6-4B0D-B970-497A572FC5ED/<private> as the current item-to-advertise.

It seems like the difference in type ('org.chromium.web-custom-data' vs 'public.html'/'public.utf8-plain-text') may be the issue.

For graphics-related bugs, please copy/paste the contents of the about:gpu
page at the end of this report.