Stop unnecessary PostTask to UI thread in SXG related code

Before NavigationLoaderOnUI, SXG related code are executed on IO thread.
So we need to use PostTask() to UI thread to get FrameTreeNode.
But now they are executed on UI thread. We don't need to use PostTask().

Bug: 824854
Change-Id: I5bff6782ec0ba9bda0d9f930d13f92d009711cd6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1873814Reviewed-by: Kunihiko Sakamoto <ksakamoto@chromium.org>
Commit-Queue: Tsuyoshi Horo <horo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708506}

content/browser/web_package/signed_exchange_handler.cc

@@ -11,7 +11,6 @@
 #include "base/metrics/histogram_functions.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/stringprintf.h"
-#include "base/task/post_task.h"
 #include "base/time/time.h"
 #include "base/trace_event/trace_event.h"
 #include "content/browser/frame_host/frame_tree_node.h"
@@ -518,12 +517,10 @@ void SignedExchangeHandler::OnCertReceived(
   //   property, or
   const std::string& stapled_ocsp_response = unverified_cert_chain_->ocsp();
 
-  base::PostTask(
-      FROM_HERE, {BrowserThread::UI},
-      base::BindOnce(&VerifyCert, certificate, url, stapled_ocsp_response,
-                     sct_list_from_cert_cbor, frame_tree_node_id_,
-                     base::BindOnce(&SignedExchangeHandler::OnVerifyCert,
-                                    weak_factory_.GetWeakPtr())));
+  VerifyCert(certificate, url, stapled_ocsp_response, sct_list_from_cert_cbor,
+             frame_tree_node_id_,
+             base::BindOnce(&SignedExchangeHandler::OnVerifyCert,
+                            weak_factory_.GetWeakPtr()));
 }
 
 // https://wicg.github.io/webpackage/draft-yasskin-http-origin-signed-responses.html#cross-origin-cert-req

content/browser/web_package/signed_exchange_reporter.cc

@@ -9,7 +9,6 @@
 
 #include "base/callback.h"
 #include "base/memory/ptr_util.h"
-#include "base/task/post_task.h"
 #include "content/browser/frame_host/frame_tree_node.h"
 #include "content/browser/web_package/signed_exchange_utils.h"
 #include "content/public/browser/browser_context.h"
@@ -118,8 +117,8 @@ bool ShouldDowngradeReport(const char* result_string,
   return false;
 }
 
-void ReportResultOnUI(int frame_tree_node_id,
-                      network::mojom::SignedExchangeReportPtr report) {
+void ReportResult(int frame_tree_node_id,
+                  network::mojom::SignedExchangeReportPtr report) {
   FrameTreeNode* frame_tree_node =
       FrameTreeNode::GloballyFindByID(frame_tree_node_id);
   if (!frame_tree_node)
@@ -212,9 +211,7 @@ void SignedExchangeReporter::ReportResultAndFinish(
     report_->elapsed_time = base::TimeTicks::Now() - request_start_;
   }
 
-  base::PostTask(FROM_HERE, {BrowserThread::UI},
-                 base::BindOnce(&ReportResultOnUI, frame_tree_node_id_,
-                                std::move(report_)));
+  ReportResult(frame_tree_node_id_, std::move(report_));
 }
 
 }  // namespace content