[Mac] Adjust omnibox decoration dragging to keep image under mouse.

chrome/browser/cocoa/location_bar/bubble_decoration.mm

Index: chrome/browser/cocoa/location_bar/bubble_decoration.mm
diff --git a/chrome/browser/cocoa/location_bar/bubble_decoration.mm b/chrome/browser/cocoa/location_bar/bubble_decoration.mm
index 5a85a9c6bf83ecd2da7ad1a32939b44bb3e43be3..5e2a9ad2789c5fa379465063a9b7afc8aff3c3c4 100644
--- a/chrome/browser/cocoa/location_bar/bubble_decoration.mm
+++ b/chrome/browser/cocoa/location_bar/bubble_decoration.mm
@@ -43,6 +43,13 @@ CGFloat BubbleDecoration::GetWidthForImageAndLabel(NSImage* image,
   return kBubblePadding + image_width + label_width;
 }
 
+NSRect BubbleDecoration::GetImageRectInFrame(NSRect frame) {
+  NSRect imageRect = NSInsetRect(frame, 0.0, kKeywordYInset);
+  if (image_)
+    imageRect.size = [image_ size];
+  return imageRect;
+}
+
 CGFloat BubbleDecoration::GetWidthForSpace(CGFloat width) {
   const CGFloat all_width = GetWidthForImageAndLabel(image_, label_);
   if (all_width <= width)