MacViews: Anchor bubbles according to the MD spec.

chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_cell.mm

Index: chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_cell.mm
diff --git a/chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_cell.mm b/chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_cell.mm
index 1a70f222639746c6ba5292f6d66ef47db6a05eaa..3046c087b36d966ff5814884b4a540c483d1e439 100644
--- a/chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_cell.mm
+++ b/chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_cell.mm
@@ -242,6 +242,17 @@ size_t CalculatePositionsInFrame(
   return NSZeroRect;
 }
 
+- (NSRect)backgroundFrameForDecoration:(LocationBarDecoration*)decoration
+                               inFrame:(NSRect)cellFrame
+                      isLeftDecoration:(BOOL*)isLeftDecoration {
+  NSRect decorationFrame =
+      [self frameForDecoration:decoration inFrame:cellFrame];
+  *isLeftDecoration =
+      std::find(leftDecorations_.begin(), leftDecorations_.end(), decoration) !=
+      leftDecorations_.end();
+  return decoration->GetBackgroundFrame(decorationFrame);
+}
+
 // Overriden to account for the decorations.
 - (NSRect)textFrameForFrame:(NSRect)cellFrame {
   // Get the frame adjusted for decorations.