Do IWYU for base/containers/contains.h in content/ and blink.

Include base/containers/contains.h in content/ and third_party/blink/
files that use base::Contains().

Bug: 970209
Change-Id: I9a60dfca9cc48c4467724fd32b1fdddddc7e551d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2893126
Reviewed-by: Kinuko Yasuda <[email protected]>
Reviewed-by: Tom Sepez <[email protected]>
Commit-Queue: Tom Sepez <[email protected]>
Auto-Submit: Lei Zhang <[email protected]>
Cr-Commit-Position: refs/heads/master@{#882665}
diff --git a/content/shell/browser/shell_platform_delegate_aura.cc b/content/shell/browser/shell_platform_delegate_aura.cc
index 13ee15e..17d5403c 100644
--- a/content/shell/browser/shell_platform_delegate_aura.cc
+++ b/content/shell/browser/shell_platform_delegate_aura.cc
@@ -4,6 +4,7 @@
 
 #include "content/shell/browser/shell_platform_delegate.h"
 
+#include "base/containers/contains.h"
 #include "content/public/browser/render_widget_host_view.h"
 #include "content/public/browser/web_contents.h"
 #include "content/shell/browser/shell.h"