Code:  ui::ModalType ExtensionInstallDialogView::GetModalType() const {
  return ui::MODAL_TYPE_WINDOW;
 }

Vulnerability Type: 
CWE ID: CWE-17
Summary: The Web Store inline-installer implementation in the Extensions UI in Google Chrome before 49.0.2623.75 does not block installations upon deletion of an installation frame, which makes it easier for remote attackers to trick a user into believing that an installation request originated from the user's next navigation target via a crafted web site.
Commit Message: Make the webstore inline install dialog be tab-modal

Also clean up a few minor lint errors while I'm in here.

BUG=550047

Review URL: https://codereview.chromium.org/1496033003

Cr-Commit-Position: refs/heads/master@{#363925}