[web browser] Some behaviors in 'Find in page' mode do not meet the requirements

[Evan Wang]

$ adb shell system-image-cli -i
current build number: 152
device name: krillin
channel: ubuntu-touch/rc-proposed/bq-aquaris.en
last update: 2015-10-16 04:40:26
version version: 152
version ubuntu: 20151016
version device: 20150821-736d127
version custom: 20150925-901-35-40-vivid

Steps to reproduce:
1. Launch web browser
2. Enable "Find in page" mode from top-right corner menu

Action 1: Typing one or more matched letters in search box, the Next/Previous chevrons is not disabled when at the top/bottom of the list, please refer to attachment 1
Expected: Next/Previous chevrons will be disabled if at the top/bottom of the list

Action 2: Typing some unmatched letters in search box, the hint text at the right is not highlighted in red, pls refer to attachment 2
Expected: If there are no matches, the hint text at the right is highlighted in red

[Brendan Donegan (brendan-donegan)]

@Evan, this is a partial duplicate of https://bugs.launchpad.net/ubuntu/+source/webbrowser-app/+bug/1511736 (for the first behaviour), please update this bug to only mention the second issue, and please don't file one bug for multiple distinct issues (even though they are related to the same test case, you should instead link both bugs to that test case)

[Olivier Tilloy (osomon)]

I added a ubuntu-ux task to let design comment on whether the hint text should really be highlighted in red when there are no matches.