[HTTPS-First Mode] Enable HFMv2 by default

Enables the HttpsFirstModeV2 feature flag by default now that the new
version matches the V1 implementation. Also explicitly disables HFMv2
in the V1 test suite (https_only_mode_browsertest.cc) to maintian
coverage for V1 for now.

Bug: 1394910
Change-Id: Ic690640e760d53d1e793bbb4559ee091dfa98d30
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4288115
Commit-Queue: Mustafa Emre Acer <meacer@chromium.org>
Auto-Submit: Chris Thompson <cthomp@chromium.org>
Reviewed-by: Mustafa Emre Acer <meacer@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1109224}

Author: christhompson

chrome/browser/ssl/https_only_mode_browsertest.cc

@@ -54,7 +54,9 @@ class HttpsOnlyModeBrowserTest : public InProcessBrowserTest {
   ~HttpsOnlyModeBrowserTest() override = default;
 
   void SetUp() override {
-    feature_list_.InitAndEnableFeature(features::kHttpsOnlyMode);
+    feature_list_.InitWithFeatures(
+        /*enabled_features=*/{features::kHttpsOnlyMode},
+        /*disabled_features=*/{features::kHttpsFirstModeV2});
     InProcessBrowserTest::SetUp();
   }
 

chrome/common/chrome_features.cc

@@ -618,7 +618,7 @@ BASE_FEATURE(kHttpsFirstModeForAdvancedProtectionUsers,
 // Enables the new implementation of HTTPS-First Mode.
 BASE_FEATURE(kHttpsFirstModeV2,
              "HttpsFirstModeV2",
-             base::FEATURE_DISABLED_BY_DEFAULT);
+             base::FEATURE_ENABLED_BY_DEFAULT);
 
 // Enables automatically upgrading main frame navigations to HTTPS.
 BASE_FEATURE(kHttpsUpgrades,