webapps: fix theme color on status bar for Galaxy devices
On Galaxy S devices (specifically the S6) on L and above, setting the theme color
too early for the status bar causes the status bar to be set to white.
Also on other devices, setting the color too early simply causes the color to be ignored
which leads to the theme color not being set properly until page load.
Fix this by setting in onResume which is late enough such that the change takes hold
but early enough such that it appears before the web app is loaded fully.
BUG=531530
Review URL: https://codereview.chromium.org/
1336913003
Cr-Commit-Position: refs/heads/master@{#348627}