clang-tidy: Use const reference for MediaTime parameter to prevent object copy

[David Kilzer (:ddkilzer)]

Running `clang-tidy -header-filter=.* -checks='-*,performance-*,-performance-noexcept-*' ...` on JavaScriptCore and WebCore source files found these unnecessary object copies in MediaTime function parameters in trunk revision r239112.

Source/JavaScriptCore/runtime/JSCJSValue.h:554:42: warning: the parameter 't' is copied for each invocation but only used as a const reference; consider making it a const reference [performance-unnecessary-value-param]
ALWAYS_INLINE JSValue jsNumber(MediaTime t)
                                         ^
                               const    &

Source/WebCore/bindings/js/JSDOMConvertNumbers.h:392:43: warning: the parameter 'value' is copied for each invocation but only used as a const reference; consider making it a const reference [performance-unnecessary-value-param]
    static JSC::JSValue convert(MediaTime value)
                                          ^
                                const    &

[David Kilzer (:ddkilzer)]

Created attachment 357582 [details]
Patch v1

[Mark Lam]

Comment on attachment 357582 [details]
Patch v1

LGTM if EWS bots are happy.

[EWS Watchlist]

Comment on attachment 357582 [details]
Patch v1

Attachment 357582 [details] did not pass mac-wk2-ews (mac-wk2):
Output: https://webkit-queues.webkit.org/results/10461730

New failing tests:
fast/forms/datalist/datalist-textinput-suggestions-order.html

[EWS Watchlist]

Created attachment 357599 [details]
Archive of layout-test-results from ews104 for mac-sierra-wk2

The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews.
Bot: ews104  Port: mac-sierra-wk2  Platform: Mac OS X 10.12.6

[David Kilzer (:ddkilzer)]

(In reply to Build Bot from comment #4)
> Created attachment 357599 [details]
> Archive of layout-test-results from ews104 for mac-sierra-wk2
> 
> The attached test failures were seen while running run-webkit-tests on the
> mac-wk2-ews.
> Bot: ews104  Port: mac-sierra-wk2  Platform: Mac OS X 10.12.6

On further analysis, this appears to be a rare flaky crash that's unrelated to this change.  I filed <rdar://problem/46819769> to track the crash internally.

[Radar WebKit Bug Importer]

<rdar://problem/46820023>

[WebKit Commit Bot]

Comment on attachment 357582 [details]
Patch v1

Clearing flags on attachment: 357582

Committed r239352: <https://trac.webkit.org/changeset/239352>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.