Remove unused include to web_test_devtools_bindings.h

This removes a dependency from shell/browser/ to shell/browser/web_test
so we can separate production from test code.

R=avi@chromium.org

Bug: 866140
Change-Id: Ia7b152db4b87a978449e7be536639c21d648f174
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2240045
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#777236}

content/shell/browser/shell.cc

@@ -41,7 +41,6 @@
 #include "content/shell/browser/web_test/secondary_test_window_observer.h"
 #include "content/shell/browser/web_test/web_test_bluetooth_chooser_factory.h"
 #include "content/shell/browser/web_test/web_test_control_host.h"
-#include "content/shell/browser/web_test/web_test_devtools_bindings.h"
 #include "content/shell/browser/web_test/web_test_javascript_dialog_manager.h"
 #include "content/shell/common/shell_switches.h"
 #include "content/shell/common/web_test/web_test_switches.h"