Remove unnecessary IndexedDB deps from content/common

These used to be necessary for enums, but those were moved to
public/platform/WebIDBTypes.h aeons ago. It looks like
content/browser/DEPS was updated but content/common/DEPS was missed.

R=jam@chromium.org

Review URL: https://codereview.chromium.org/966463004

Cr-Commit-Position: refs/heads/master@{#319197}

content/common/DEPS

@@ -20,8 +20,6 @@ include_rules = [
   "+third_party/WebKit/public/platform/WebGeofencingEventType.h",
   "+third_party/WebKit/public/platform/WebGraphicsContext3D.h",
   "+third_party/WebKit/public/platform/WebHTTPBody.h",
-  "+third_party/WebKit/public/platform/WebIDBCursor.h",
-  "+third_party/WebKit/public/platform/WebIDBDatabase.h",
   "+third_party/WebKit/public/platform/WebIDBTypes.h",
   "+third_party/WebKit/public/platform/WebLockOrientationError.h",
   "+third_party/WebKit/public/platform/WebPageVisibilityState.h",