Move more vector icons to more appropriate directories.

ui/vector_icons/BUILD.gn

Index: ui/vector_icons/BUILD.gn
diff --git a/ui/vector_icons/BUILD.gn b/ui/vector_icons/BUILD.gn
index c299793bdac314f5bbd52448ed92f067a10106c9..44553f42b1b2387bcca365863af37052d3f0b58e 100644
--- a/ui/vector_icons/BUILD.gn
+++ b/ui/vector_icons/BUILD.gn
@@ -2,6 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/util/branding.gni")
 import("//ui/vector_icons/vector_icons.gni")
 
 aggregate_vector_icons("ui_vector_icons") {
@@ -10,6 +11,19 @@ aggregate_vector_icons("ui_vector_icons") {
   icons = [
     "close.1x.icon",
     "close.icon",
+    "error_circle.icon",

[sky, 2017/02/13 21:35:38]

Why do we have this icons in ui instead of media?

[Evan Stade, 2017/02/13 21:53:33]

Mainly because it's a generic MD icon and therefore I suspect it will be reused
by some other piece of code eventually. In my experience when someone needs this
icon they will almost certainly not look in media/ for it and they'll end up
adding it twice.

[sky, 2017/02/13 23:28:43]

Sorry for not being clear. I mean all these icons. They seem media specific and
should be in media, not here.

[Evan Stade, 2017/02/13 23:51:47]

Which ones do you mean? Location, extension, notifications, protocol etc. are
not related to media. The media router ones are used in browser ui as well as
being referenced in media/remoting. c/b doesn't depend on media/. Should it? I
dunno. 

+    "extension.icon",
+    "location_on.icon",
+    "media_router_active.icon",
+    "media_router_error.icon",
+    "media_router_idle.icon",
+    "media_router_warning.icon",
+    "microphone.icon",
+    "midi.icon",
+    "notifications.icon",
+    "protocol_handler.icon",
+    "videocam.icon",
+    "warning.icon",
   ]
 }