[Views] Center bubble title text vertically when title icon is tall.

chrome/browser/ui/views/extensions/extension_installed_bubble_view.cc

Index: chrome/browser/ui/views/extensions/extension_installed_bubble_view.cc
diff --git a/chrome/browser/ui/views/extensions/extension_installed_bubble_view.cc b/chrome/browser/ui/views/extensions/extension_installed_bubble_view.cc
index 8ae8305526e276e094d61bef0219db008875b186..d74aa28e0c7b996a6b183bb21f9029fbaa1f20fa 100644
--- a/chrome/browser/ui/views/extensions/extension_installed_bubble_view.cc
+++ b/chrome/browser/ui/views/extensions/extension_installed_bubble_view.cc
@@ -218,7 +218,6 @@ bool ExtensionInstalledBubbleView::ShouldShowCloseButton() const {
 }
 
 void ExtensionInstalledBubbleView::Init() {
-  gfx::Insets insets = margins();
   UpdateAnchorView();
 
   // The Extension Installed bubble takes on various forms, depending on the
@@ -238,9 +237,6 @@ void ExtensionInstalledBubbleView::Init() {
   //     or a link to configure the keybinding shortcut (if one exists).
   // Extra info can include a promo for signing into sync.
 
-  // Move explanatory text closer to the title.

[Evan Stade, 2016/05/04 01:35:29]

this was previously necessary because the title text was aligned to the top of
the icon, which left a bit of space beneath the text and it looked more natural
not to have a top inset on the content.

It broke the footnote view because that view reuses the content margins
(actually, I'm to blame for this).

This patch is probably a better way to fix this. Here's the before/after*:
https://screenshot.googleplex.com/06FAiVTtoGS.png

*I had to increase the width of the bubble to make the title fit on one line,
since "Chromium" is longer than "Chrome". Here's what it actually ends up
looking like without the extra horizontal space (title therefore wrapping): 
https://screenshot.googleplex.com/5rBVxuX7qOr.png

-  set_margins(gfx::Insets(0, insets.left(), insets.bottom(), insets.right()));
-
   std::unique_ptr<views::BoxLayout> layout(
       new views::BoxLayout(views::BoxLayout::kVertical, 0, 0,
                            views::kRelatedControlVerticalSpacing));