Auto merge of #12441 - aravind-pg:referrer-pol-header, r=jdm

Implement referrer policy delivery by header

Adds a new `Option<ReferrerPolicy>` field to Document and sets it appropriately in `ScriptThread::load` if a Referrer-Policy header is present.

r? @jdm

<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #11860
- [X] There are tests for these changes

<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/12441)
<!-- Reviewable:end -->

1 files changed, 24 insertions, 4 deletions

diff --git a/components/script/script_thread.rs b/components/script/script_thread.rs
index aeed396fbb1..07779fbebd2 100644
--- a/components/script/script_thread.rs
+++ b/components/script/script_thread.rs
@@ -51,8 +51,8 @@ use dom::worker::TrustedWorkerAddress;
 use euclid::Rect;
 use euclid::point::Point2D;
 use gfx_traits::LayerId;
-use hyper::header::{ContentType, HttpDate};
-use hyper::header::{Headers, LastModified};
+use hyper::header::{ContentType, Headers, HttpDate, LastModified};
+use hyper::header::{ReferrerPolicy as ReferrerPolicyHeader};
 use hyper::method::Method;
 use hyper::mime::{Mime, SubLevel, TopLevel};
 use ipc_channel::ipc::{self, IpcSender};
@@ -65,7 +65,7 @@ use js::jsval::UndefinedValue;
 use js::rust::Runtime;
 use mem::heap_size_of_self_and_children;
 use msg::constellation_msg::{FrameType, LoadData, PanicMsg, PipelineId, PipelineNamespace};
-use msg::constellation_msg::{SubpageId, WindowSizeType};
+use msg::constellation_msg::{ReferrerPolicy, SubpageId, WindowSizeType};
 use net_traits::LoadData as NetLoadData;
 use net_traits::bluetooth_thread::BluetoothMethodMsg;
 use net_traits::image_cache_thread::{ImageCacheChan, ImageCacheResult, ImageCacheThread};
@@ -1716,6 +1716,25 @@ impl ScriptThread {
             None => None,
         };
 
+        let referrer_policy = if let Some(headers) = metadata.headers {
+            headers.get::<ReferrerPolicyHeader>().map(|h| match *h {
+                ReferrerPolicyHeader::NoReferrer =>
+                    ReferrerPolicy::NoReferrer,
+                ReferrerPolicyHeader::NoReferrerWhenDowngrade =>
+                    ReferrerPolicy::NoReferrerWhenDowngrade,
+                ReferrerPolicyHeader::SameOrigin =>
+                    ReferrerPolicy::SameOrigin,
+                ReferrerPolicyHeader::Origin =>
+                    ReferrerPolicy::Origin,
+                ReferrerPolicyHeader::OriginWhenCrossOrigin =>
+                    ReferrerPolicy::OriginWhenCrossOrigin,
+                ReferrerPolicyHeader::UnsafeUrl =>
+                    ReferrerPolicy::UnsafeUrl,
+            })
+        } else {
+            None
+        };
+
         let document = Document::new(window.r(),
                                      Some(&browsing_context),
                                      Some(final_url.clone()),
@@ -1724,7 +1743,8 @@ impl ScriptThread {
                                      last_modified,
                                      DocumentSource::FromParser,
                                      loader,
-                                     referrer);
+                                     referrer,
+                                     referrer_policy);
         if using_new_context {
             browsing_context.init(&document);
         } else {