Browser::GetDisplayMode supports minimal-ui

The method Browser::GetDisplayMode previously returned
kStandalone for non-full-screen app windows, even if they
contained minimal-ui controls.

Bug: 1109522
Change-Id: I151e68bdbcacb0aa73c15152eb462bc5d5901644
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2318848
Commit-Queue: Eric Willigers <ericwilligers@chromium.org>
Reviewed-by: Alan Cutter <alancutter@chromium.org>
Reviewed-by: Peter Boström <pbos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#792107}

chrome/browser/ui/browser.cc

@@ -1954,8 +1954,11 @@ blink::mojom::DisplayMode Browser::GetDisplayMode(
   if (window_->IsFullscreen())
     return blink::mojom::DisplayMode::kFullscreen;
 
-  if (is_type_app() || is_type_devtools() || is_type_app_popup())
+  if (is_type_app() || is_type_devtools() || is_type_app_popup()) {
+    if (app_controller_ && app_controller_->HasMinimalUiButtons())
+      return blink::mojom::DisplayMode::kMinimalUi;
     return blink::mojom::DisplayMode::kStandalone;
+  }
 
   return blink::mojom::DisplayMode::kBrowser;
 }

chrome/browser/ui/web_applications/web_app_browsertest.cc

@@ -274,7 +274,15 @@ IN_PROC_BROWSER_TEST_P(WebAppBrowserTest, HasMinimalUiButtons) {
     tester.ExpectUniqueSample(kLaunchWebAppDisplayModeHistogram, display_mode,
                               1);
 
-    return app_browser->app_controller()->HasMinimalUiButtons();
+    bool matches;
+    EXPECT_TRUE(ExecuteScriptAndExtractBool(
+        app_browser->tab_strip_model()->GetActiveWebContents(),
+        "window.domAutomationController.send(window.matchMedia('(display-mode: "
+        "minimal-ui)').matches)",
+        &matches));
+    EXPECT_EQ(app_browser->app_controller()->HasMinimalUiButtons(), matches);
+
+    return matches;
   };
 
   EXPECT_TRUE(has_buttons(DisplayMode::kBrowser,