Refactor postMessage for out-of-process iframes.

This CL moves cross-process postMessage plumbing from RenderView
to RenderFrame:

- The renderer-to-browser RouteMessageEvent message is now sent
  through RenderFrameProxy rather than a swapped-out RenderView.

- The bulk of WebContentsImpl::RouteMessageEvent is moved into
  RenderFrameProxyHost::RouteMessageEvent.  Unfortunately, we still
  need to call up to WebContents for dealing with <webview> and
  on-demand creation of swapped-out RVs for the opener chain.  This
  will be cleaned up as part of https://crbug.com/225940.

- the browser-to-renderer PostMessageEvent message is now handled in
  RenderFrameImpl::OnPostMessageEvent, instead of RenderViewImpl.

These changes make it possible to send messages between cross-process
subframes when in --site-per-process mode.  This is exercised in a new
test, SitePerProcessBrowserTest.SubframePostMessage.  More work will
be needed to support postMessages involving subframes in cross-process
openers (see https://crbug.com/225940 and https://crbug.com/423587).

With this change, the RFHM::SupportCrossProcessPostMessage test now
works in --site-per-process mode, so it is enabled on the Site
Isolation FYI bots.

BUG=389721
TBR=jam@chromium.org

Review URL: https://codereview.chromium.org/1046933005

Cr-Commit-Position: refs/heads/master@{#324341}

1 files changed, 0 insertions, 1 deletions

diff --git a/content/common/swapped_out_messages.cc b/content/common/swapped_out_messages.cc
index 3cb20a5..a89564d 100644
--- a/content/common/swapped_out_messages.cc
+++ b/content/common/swapped_out_messages.cc
@@ -31,7 +31,6 @@ bool SwappedOutMessages::CanSendWhileSwappedOut(const IPC::Message* msg) {
     case ViewHostMsg_DocumentDetached::ID:
     // Allow cross-process JavaScript calls.
     case ViewHostMsg_RouteCloseEvent::ID:
-    case ViewHostMsg_RouteMessageEvent::ID:
     // Handled by RenderFrameHost.
     case FrameHostMsg_BeforeUnload_ACK::ID:
     case FrameHostMsg_SwapOut_ACK::ID: