Updates Zoom bubble layout and adds +/- buttons

chrome/app/vector_icons/BUILD.gn

Index: chrome/app/vector_icons/BUILD.gn
diff --git a/chrome/app/vector_icons/BUILD.gn b/chrome/app/vector_icons/BUILD.gn
index 0ab6bfa571ebfd7a7cce5f6549d329a3684f56a9..d10f9be44be5003262998b691a43095f853475f8 100644
--- a/chrome/app/vector_icons/BUILD.gn
+++ b/chrome/app/vector_icons/BUILD.gn
@@ -50,6 +50,8 @@ aggregate_vector_icons("chrome_vector_icons") {
     "incognito.icon",
     "laptop.icon",
     "lock.icon",
+    "minus.1x.icon",

[Evan Stade, 2017/04/27 17:29:38]

could you call this zoom_minus and zoom_plus? There are likely many places we
might use plus and minus icons in Chrome but their exact appearance might
differ. Plus this makes it immediately obvious how these are used for now, and
if we later want to reuse them for something not zoom related we can make that
switch easily.

(other icons with generic names here like "code" are copying the names on
go/icons)

[varkha, 2017/04/28 02:06:13]

Those are already taken (by magnifying glass icons). Since I based those on the
icons I've found on go/icons I will rename them to generic add / remove.

+    "minus.icon",
     "mixed_content.icon",
     "my_location.icon",
     "navigate_home.1x.icon",
@@ -62,6 +64,8 @@ aggregate_vector_icons("chrome_vector_icons") {
     "overflow_chevron.icon",
     "paintbrush.icon",
     "photo_camera.icon",
+    "plus.1x.icon",
+    "plus.icon",
     "remove_box.icon",
     "sad_tab.icon",
     "settings.icon",