Get latest page always from wayback machine

By deleting timestamp value from wayback query, we can get latest saved page.
fix brave/brave-browser#14843

Author: simonhong

components/brave_wayback_machine/brave_wayback_machine_utils.cc

@@ -28,3 +28,15 @@ bool IsWaybackMachineDisabledFor(const GURL& url) {
 
   return false;
 }
+
+GURL FixupWaybackQueryURL(const GURL& url) {
+  // Get latest page always from wayback machine by invalidating timestamp
+  // value in query string.
+  GURL fixed_url = url;
+  std::string unused;
+  if (net::GetValueForKeyInQuery(fixed_url, "timestamp", &unused)) {
+    fixed_url = net::AppendOrReplaceQueryParameter(fixed_url, "timestamp", "");
+  }
+
+  return fixed_url;
+}

components/brave_wayback_machine/brave_wayback_machine_utils.h

@@ -9,5 +9,6 @@
 class GURL;
 
 bool IsWaybackMachineDisabledFor(const GURL& url);
+GURL FixupWaybackQueryURL(const GURL& url);
 
 #endif  // BRAVE_COMPONENTS_BRAVE_WAYBACK_MACHINE_BRAVE_WAYBACK_MACHINE_UTILS_H_

components/brave_wayback_machine/brave_wayback_machine_utils_unittest.cc

@@ -4,6 +4,8 @@
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "brave/components/brave_wayback_machine/brave_wayback_machine_utils.h"
+#include "brave/components/brave_wayback_machine/url_constants.h"
+#include "net/base/url_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "url/gurl.h"
 
@@ -23,3 +25,18 @@ TEST(BraveWaybackMachineUtilsTest, LocalHostDisabledTest) {
   EXPECT_FALSE(
       IsWaybackMachineDisabledFor(GURL("https://archive.org/foobar.html")));
 }
+
+TEST(BraveWaybackMachineUtilsTest, FixupQueryURLTest) {
+  GURL wayback_fetch_url(std::string(kWaybackQueryURL) +
+                         "https://www.example.com?&timestamp=20160101");
+  std::string timestamp_value;
+  EXPECT_TRUE(net::GetValueForKeyInQuery(wayback_fetch_url, "timestamp",
+                                         &timestamp_value));
+  EXPECT_EQ("20160101", timestamp_value);
+
+  wayback_fetch_url = FixupWaybackQueryURL(wayback_fetch_url);
+  EXPECT_TRUE(net::GetValueForKeyInQuery(wayback_fetch_url, "timestamp",
+                                         &timestamp_value));
+  // Check value is empty.
+  EXPECT_EQ("", timestamp_value);
+}

components/brave_wayback_machine/wayback_machine_url_fetcher.cc

@@ -9,9 +9,10 @@
 
 #include "base/bind.h"
 #include "base/json/json_reader.h"
+#include "brave/components/brave_wayback_machine/brave_wayback_machine_utils.h"
 #include "brave/components/brave_wayback_machine/url_constants.h"
-#include "net/traffic_annotation/network_traffic_annotation.h"
 #include "net/base/load_flags.h"
+#include "net/traffic_annotation/network_traffic_annotation.h"
 #include "services/network/public/cpp/resource_request.h"
 #include "services/network/public/cpp/shared_url_loader_factory.h"
 #include "services/network/public/cpp/simple_url_loader.h"
@@ -52,14 +53,12 @@ WaybackMachineURLFetcher::WaybackMachineURLFetcher(
       url_loader_factory_(std::move(url_loader_factory)) {
 }
 
-WaybackMachineURLFetcher::~WaybackMachineURLFetcher() {
-}
+WaybackMachineURLFetcher::~WaybackMachineURLFetcher() = default;
 
 void WaybackMachineURLFetcher::Fetch(const GURL& url) {
   auto request = std::make_unique<network::ResourceRequest>();
-  std::string wayback_fetch_url =
-      std::string(kWaybackQueryURL) + url.spec();
-  request->url = GURL(wayback_fetch_url);
+  const GURL wayback_fetch_url(std::string(kWaybackQueryURL) + url.spec());
+  request->url = FixupWaybackQueryURL(wayback_fetch_url);
   request->credentials_mode = network::mojom::CredentialsMode::kOmit;
   request->load_flags = net::LOAD_DO_NOT_SAVE_COOKIES;
   wayback_url_loader_ = network::SimpleURLLoader::Create(