Fix #5578

[kaycebasques]

What's changed, or what was fixed?

• explains why the size column has 2 values when in large request row mode

Fixes: #5578

Target Live Date: 2018-06-21

• This has been reviewed and approved by (NAME)
• I have run npm test locally and all tests pass.
• I have added the appropriate type-something label.
• I've staged the site and manually verified that my content displays correctly.

CC: @petele

[WebFundBot]

Whoops!

There were 3 warnings that will prevent this PR from being merged. Please take a look, and either fix, or provide a justification for why they can't be fixed.

WARNINGS
src/content/en/tools/chrome-devtools/network-performance/imgs/small-request-rows.png - Unable to read file stats: ENOENT: no such file or directory, stat 'src/content/en/tools/chrome-devtools/network-performance/imgs/small-request-rows.png'
src/content/en/tools/chrome-devtools/network-performance/reference.md#L667 - Common typo found: 'ServiceWorker' Should it be 'service worker'? Capitalize Service if it's the first word in the sentence.
src/content/en/tools/chrome-devtools/network-performance/reference.md#L668 - Common typo found: 'ServiceWorker' Should it be 'service worker'? Capitalize Service if it's the first word in the sentence.

[WebFundBot]

🎉 This has been pushed live to https://developers.google.com/web/