[Mac Task Manager] Force tasks to be in black.

Bug: 1018333
Change-Id: I862c55482fabcdb1e8618f316969937957f1e9b8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1880546
Auto-Submit: Avi Drissman <avi@chromium.org>
Commit-Queue: Leonard Grey <lgrey@chromium.org>
Reviewed-by: Leonard Grey <lgrey@chromium.org>
Cr-Commit-Position: refs/heads/master@{#709661}

chrome/browser/ui/cocoa/task_manager_mac.mm

@@ -555,11 +555,14 @@ bool ShouldUseViewsTaskManager() {
     NSButtonCell* buttonCell = static_cast<NSButtonCell*>(cell);
     NSString* title = [self modelTextForRow:rowIndex
                                     column:[[tableColumn identifier] intValue]];
-    [buttonCell setTitle:title];
-    [buttonCell
-        setImage:taskManagerMac_->GetImageForRow(viewToModelMap_[rowIndex])];
-    [buttonCell setRefusesFirstResponder:YES];  // Don't push in like a button.
-    [buttonCell setHighlightsBy:NSNoCellMask];
+    buttonCell.attributedTitle = [[[NSAttributedString alloc]
+        initWithString:title
+            attributes:@{NSForegroundColorAttributeName : [NSColor blackColor]}]
+        autorelease];
+    buttonCell.image =
+        taskManagerMac_->GetImageForRow(viewToModelMap_[rowIndex]);
+    buttonCell.refusesFirstResponder = YES;  // Don't push in like a button.
+    buttonCell.highlightsBy = NSNoCellMask;
   }
 
   return cell;