Squelch context menus on the OSX App List when both buttons are pressed.

ui/app_list/cocoa/apps_grid_controller_unittest.mm

Index: ui/app_list/cocoa/apps_grid_controller_unittest.mm
diff --git a/ui/app_list/cocoa/apps_grid_controller_unittest.mm b/ui/app_list/cocoa/apps_grid_controller_unittest.mm
index 2815882a50d8e3f99e0bec78196d674daa0ab5f5..a01524644e11618c51b954740191ef7d1cb5c431 100644
--- a/ui/app_list/cocoa/apps_grid_controller_unittest.mm
+++ b/ui/app_list/cocoa/apps_grid_controller_unittest.mm
@@ -983,6 +983,13 @@ TEST_F(AppsGridControllerTest, ContextMenus) {
   menu = [page menuForEvent:mouse_at_cell_1];
   EXPECT_EQ(1, [menu numberOfItems]);
   EXPECT_NSEQ(@"Menu For: Item Two", [[menu itemAtIndex:0] title]);
+
+  // Test that a button being held down with the left button does not also show
+  // a context menu.
+  [GetItemViewAt(0) highlight:YES];
+  EXPECT_FALSE([page menuForEvent:mouse_at_cell_0]);
+  [GetItemViewAt(0) highlight:NO];
+  EXPECT_TRUE([page menuForEvent:mouse_at_cell_0]);
 }
 
 }  // namespace test