Use vector image resources in extension install dialog.

Use vector image resources in extension install dialog.

This also fixes this image for non-1x scale factors. This UI is visible
for example when installing the "Rock Solid Scale Reader" app.

BUG=505953
Committed: https://crrev.com/6e73a6cccf0b60a64d862cfb7763937c25fbcd73
Cr-Commit-Position: refs/heads/master@{#342679}

[Evan Stade, 2015-08-10 17:13:39]

estade@chromium.org changed reviewers:
+ sky@chromium.org

[Evan Stade, 2015-08-10 17:13:40]

https://codereview.chromium.org/1276903003/diff/1/chrome/browser/ui/views/ext...
File chrome/browser/ui/views/extensions/extension_install_dialog_view.cc (left):

https://codereview.chromium.org/1276903003/diff/1/chrome/browser/ui/views/ext...
chrome/browser/ui/views/extensions/extension_install_dialog_view.cc:534:
icon->SetHorizontalAlignment(views::ImageView::CENTER);
unrelated, but these are already the defaults

https://codereview.chromium.org/1276903003/diff/1/chrome/browser/ui/views/ext...
chrome/browser/ui/views/extensions/extension_install_dialog_view.cc:735:
std::max(gfx::GetStringWidth(
this was buggy; it neglects insets but papers over it with the
views::kRelatedControlHorizontalSpacing padding.

[sky, 2015-08-10 19:27:21]

LGTM

[Evan Stade, 2015-08-10 20:05:00]

The CQ bit was checked by estade@chromium.org

[commit-bot: I haz the power, 2015-08-10 20:05:40]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1276903003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1276903003/1

[commit-bot: I haz the power, 2015-08-10 20:11:47]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-08-10 20:12:27]

Patchset 1 (id:??) landed as
https://crrev.com/6e73a6cccf0b60a64d862cfb7763937c25fbcd73
Cr-Commit-Position: refs/heads/master@{#342679}