Fix notification view message sizing.

The MessageView renders a drop shadow[1] on Windows that adds insets to
the content view of notifications. We need to set the reduced width as
size of the |message_view_| to correctly calculate bounds and wrapping
behavior.

Before: https://imgur.com/pftjgrG
After: https://imgur.com/wEsv5EN

[1]: https://cs.chromium.org/chromium/src/ui/message_center/views/message_view.cc?l=107&rcl=2b3975c5de2635f5a436fb950b42fd5b657ae09f

Bug: 1001047
Change-Id: I8a8b75aea4bdb800596d7790fafa541f2b50a6e7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1895333Reviewed-by: Peter Beverloo <peter@chromium.org>
Commit-Queue: Richard Knoll <knollr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#712962}

ui/message_center/views/notification_view_md.cc

@@ -1246,28 +1246,24 @@ void NotificationViewMD::UpdateViewForExpandedState(bool expanded) {
       list_items_count_ -
       (expanded ? item_views_.size() : kMaxLinesForMessageView));
 
-  right_content_->SetVisible(icon_view_ &&
-                             (!hide_icon_on_expanded_ || !expanded));
-  if (right_content_->GetVisible()) {
-    left_content_->SetBorder(
-        views::CreateEmptyBorder(kLeftContentPaddingWithIcon));
-
-    // TODO(tetsui): Workaround https://crbug.com/682266 by explicitly setting
-    // the width.
-    // Ideally, we should fix the original bug, but it seems there's no obvious
-    // solution for the bug according to https://crbug.com/678337#c7, we should
-    // ensure that the change won't break any of the users of BoxLayout class.
-    if (title_view_)
-      title_view_->SizeToFit(kMessageViewWidthWithIcon);
-    if (message_view_)
-      message_view_->SizeToFit(kMessageViewWidthWithIcon);
-  } else {
-    left_content_->SetBorder(views::CreateEmptyBorder(kLeftContentPadding));
-    if (title_view_)
-      title_view_->SizeToFit(kMessageViewWidth);
-    if (message_view_)
-      message_view_->SizeToFit(kMessageViewWidth);
-  }
+  bool has_icon = icon_view_ && (!hide_icon_on_expanded_ || !expanded);
+  right_content_->SetVisible(has_icon);
+  left_content_->SetBorder(views::CreateEmptyBorder(
+      has_icon ? kLeftContentPaddingWithIcon : kLeftContentPadding));
+
+  // TODO(tetsui): Workaround https://crbug.com/682266 by explicitly setting
+  // the width.
+  // Ideally, we should fix the original bug, but it seems there's no obvious
+  // solution for the bug according to https://crbug.com/678337#c7, we should
+  // ensure that the change won't break any of the users of BoxLayout class.
+  const int message_view_width =
+      (has_icon ? kMessageViewWidthWithIcon : kMessageViewWidth) -
+      GetInsets().width();
+  if (title_view_)
+    title_view_->SizeToFit(message_view_width);
+  if (message_view_)
+    message_view_->SizeToFit(message_view_width);
+
   content_row_->InvalidateLayout();
 }