Remove |RenderViewImpl::enabled_bindings_| field.

It seems that after https://codereview.chromium.org/2566583002 it
isn't needed anymore.

No change in behavior.

Bug: 
Change-Id: I9676e8e98a8d289e84ac65c34614e0f3d18c2767
Reviewed-on: https://chromium-review.googlesource.com/590247Reviewed-by: Sam McNally <sammc@chromium.org>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Commit-Queue: Andrey Kraynov <iceman@yandex-team.ru>
Cr-Commit-Position: refs/heads/master@{#504326}

content/renderer/render_view_impl.cc

@@ -57,7 +57,6 @@
 #include "content/common/render_message_filter.mojom.h"
 #include "content/common/view_messages.h"
 #include "content/public/common/associated_interface_provider.h"
-#include "content/public/common/bindings_policy.h"
 #include "content/public/common/browser_side_navigation_policy.h"
 #include "content/public/common/content_client.h"
 #include "content/public/common/content_constants.h"
@@ -529,7 +528,6 @@ RenderViewImpl::RenderViewImpl(CompositorDependencies* compositor_deps,
                    params.never_visible),
       webkit_preferences_(params.web_preferences),
       send_content_state_immediately_(false),
-      enabled_bindings_(0),
       send_preferred_size_changes_(false),
       navigation_gesture_(NavigationGestureUnknown),
       history_list_offset_(-1),

content/renderer/render_view_impl.h

@@ -627,10 +627,6 @@ class CONTENT_EXPORT RenderViewImpl : public RenderWidget,
   // false, but set to true by some tests.
   bool send_content_state_immediately_;
 
-  // Bitwise-ORed set of extra bindings that have been enabled.  See
-  // BindingsPolicy for details.
-  int enabled_bindings_;
-
   // If true, we send IPC messages when |preferred_size_| changes.
   bool send_preferred_size_changes_;