Convert FrameHostMsg_DidAddMessageToConsole to Mojo.

Note: Since this required changing the test
RenderViewImplTest.DispatchBeforeUnloadCanDetachFrame, I manually
re-introduced https://crbug.com/666714 locally (the bug the test was
added for), and reran the test to confirm that it still covers the bug.

Bug: 786836
Change-Id: I110668fa6f0f261fd2ac36bb91a8d8b31c99f4f1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1526270
Commit-Queue: Lowell Manners <lowell@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Camille Lamy <clamy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#653137}
bool MaybeGetOverriddenURL(WebDocumentLoader* document_loader, GURL* output) {
  DocumentState* document_state =
      DocumentState::FromDocumentLoader(document_loader);

  if (document_state->was_load_data_with_base_url_request()) {
    *output = document_state->data_url();
    return true;
  }

  if (document_loader->HasUnreachableURL()) {
    *output = document_loader->UnreachableURL();
    return true;
  }

  return false;
}

bool MaybeGetOverriddenURL(WebDocumentLoader* document_loader, GURL* output) {
  DocumentState* document_state =
      DocumentState::FromDocumentLoader(document_loader);

  if (document_state->was_load_data_with_base_url_request()) {
    *output = document_state->data_url();
    return true;
  }

  if (document_loader->HasUnreachableURL()) {
    *output = document_loader->UnreachableURL();
    return true;
  }

  return false;
}
