Set 'ResourceRequest::requestorOrigin' in Blink.

Set 'ResourceRequest::requestorOrigin' in Blink.

We're currently setting the requestor origin in 'RenderFrameImpl', which
is the wrong place to encode a request's initiator data. This patch moves
it to 'FrameFetchContext' in Blink, and changes the implementation to
distinguish between "empty" initiators and "unique" initiators. A future
patch will use that distinction to determine whether a request is user-
initiated (omnibox), and should be considered "SameSite" for the purposes
of cookies.

BUG=625969
R=clamy@chromium.org,nasko@chromium.org

[Mike West, 2016-07-06 12:18:04]

mkwst@chromium.org changed reviewers:
+ jochen@chromium.org

[Mike West, 2016-07-06 12:18:05]

jochen@: Mind taking a look at //third_party/WebKit?

clamy@, nasko@: Would you mind looking at //content? This starts to address
Nasko's complaints about https://codereview.chromium.org/2099243002; a
subsequent patch will push the `nullptr`/unique distinction higher up the stack
rather than setting the initiator to the current document's origin.

[jochen (gone - plz use gerrit), 2016-07-06 12:21:37]

lgtm

[clamy, 2016-07-07 14:59:08]

Thanks! A few questions below.

https://codereview.chromium.org/2128503002/diff/20001/content/renderer/render...
File content/renderer/render_frame_impl.cc (right):

https://codereview.chromium.org/2128503002/diff/20001/content/renderer/render...
content/renderer/render_frame_impl.cc:3932:
DCHECK(!request.requestorOrigin().isNull() ||
Just to check, the patch does not currently expect to get a null initiator, but
eventually we should be able to have it?

https://codereview.chromium.org/2128503002/diff/20001/third_party/WebKit/Sour...
File third_party/WebKit/Source/platform/exported/WebSecurityOrigin.cpp (right):

https://codereview.chromium.org/2128503002/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/platform/exported/WebSecurityOrigin.cpp:103: return
!m_private && m_private->isUnique();
Shouldn't it be m_private && m_private->isUnique() or !m_private ||
m_private->isUnique() ?

[nasko, 2016-07-18 23:34:43]

Apologies for the slow response. content/ hasn't changed much really : ).

https://codereview.chromium.org/2128503002/diff/40001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/loader/FrameFetchContext.cpp (right):

https://codereview.chromium.org/2128503002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/loader/FrameFetchContext.cpp:762:
request.setRequestorOrigin(SecurityOrigin::create(m_document->url()));
I don't grok Blink as well, but if the document origin is unique, shouldn't we
be setting it to SecurityOrigin::createUnique()?

https://codereview.chromium.org/2128503002/diff/40001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/loader/FrameLoadRequest.cpp (right):

https://codereview.chromium.org/2128503002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/loader/FrameLoadRequest.cpp:49:
printf("FrameLoadRequest: %s\n",
resourceRequest.url().getString().utf8().data());
nit: Those will be gone before commit, right ;)