DevTools: speculative fix for crash in NetworkHandler::Disable

This keeps BrowserContext* and StoragePartition* instead of
RenderProcessHost* in an attemp to resolve UAF of RenderProcessHost
upon closure of DevTools front-end.

Bug: 801117, 783067, 780694
Change-Id: I6c2cca60cc0c29f0949d189cf918769059f80c1b
Reviewed-on: https://chromium-review.googlesource.com/876657
Commit-Queue: Andrey Kosyakov <caseq@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#531157}
void PageHandler::PrintToPDF(Maybe<bool> landscape,
                             Maybe<bool> display_header_footer,
                             Maybe<bool> print_background,
                             Maybe<double> scale,
                             Maybe<double> paper_width,
                             Maybe<double> paper_height,
                             Maybe<double> margin_top,
                             Maybe<double> margin_bottom,
                             Maybe<double> margin_left,
                             Maybe<double> margin_right,
                             Maybe<String> page_ranges,
                             Maybe<bool> ignore_invalid_page_ranges,
                             Maybe<String> header_template,
                             Maybe<String> footer_template,
                             std::unique_ptr<PrintToPDFCallback> callback) {
  callback->sendFailure(Response::Error("PrintToPDF is not implemented"));
  return;
}

void PageHandler::PrintToPDF(Maybe<bool> landscape,
                             Maybe<bool> display_header_footer,
                             Maybe<bool> print_background,
                             Maybe<double> scale,
                             Maybe<double> paper_width,
                             Maybe<double> paper_height,
                             Maybe<double> margin_top,
                             Maybe<double> margin_bottom,
                             Maybe<double> margin_left,
                             Maybe<double> margin_right,
                             Maybe<String> page_ranges,
                             Maybe<bool> ignore_invalid_page_ranges,
                             Maybe<String> header_template,
                             Maybe<String> footer_template,
                             std::unique_ptr<PrintToPDFCallback> callback) {
  callback->sendFailure(Response::Error("PrintToPDF is not implemented"));
  return;
}
