Fix the candidate window position of IME in Retina display.

content/browser/renderer_host/render_widget_host_view_mac.mm

Index: content/browser/renderer_host/render_widget_host_view_mac.mm
diff --git a/content/browser/renderer_host/render_widget_host_view_mac.mm b/content/browser/renderer_host/render_widget_host_view_mac.mm
index cb3ecf5cb2e6e14f873954cf6c5ea4f0da88b82e..eae7ba2a4a70dc346e931069705d597c45492e81 100644
--- a/content/browser/renderer_host/render_widget_host_view_mac.mm
+++ b/content/browser/renderer_host/render_widget_host_view_mac.mm
@@ -2812,9 +2812,8 @@ extern NSString *NSTextInputReplacementRangeAttributeName;
   // flip the coordinate system and then convert it into screen coordinates for
   // return.
   NSRect viewFrame = [self frame];
-  rect.origin.y = NSHeight(viewFrame) - rect.origin.y;
-  rect.origin.y -= rect.size.height;
-  rect = [self convertRectToBase:rect];
+  rect.origin.y = NSHeight(viewFrame) - NSMaxY(rect);
+  rect = [self convertRect:rect toView:nil];
   rect.origin = [[self window] convertBaseToScreen:rect.origin];
   return rect;
 }