Mac: Make the Cocoa blocked plugins bubble shorter.

Now that flash is the only plugin, this dialog has a lot less to say,
and has too much unwanted white space.

The height of the Cocoa bubble is a hardcoded magic number specific to
this dialog. Make it smaller. The dialog will be replaced with
a toolkit-views version soon.

Bug: 773218
Change-Id: Ie828c7d88415c3e1d42c7e280fdd5bae60e8cb71
Reviewed-on: https://chromium-review.googlesource.com/746461Reviewed-by: Bret Sepulveda <bsep@chromium.org>
Commit-Queue: Trent Apted <tapted@chromium.org>
Cr-Commit-Position: refs/heads/master@{#512964}

chrome/browser/ui/cocoa/content_settings/blocked_plugin_bubble_controller.mm

@@ -45,7 +45,7 @@ void SetControlSize(NSControl* control, NSControlSize control_size) {
   // The size of this bubble, and the other layout constants elsewhere in this
   // file, were lifted from ContentBlockedPlugins.xib
   base::scoped_nsobject<InfoBubbleWindow> window([[InfoBubbleWindow alloc]
-      initWithContentRect:NSMakeRect(0, 0, 314, 179)
+      initWithContentRect:NSMakeRect(0, 0, 314, 145)
                 styleMask:NSBorderlessWindowMask
                   backing:NSBackingStoreBuffered
                     defer:NO]);