Desktop PWAs and shortcut windows use WebAppBrowserController

We enable the flag DesktopPWAsUnifiedUiController

Web apps (PWAs and shortcuts) now use WebAppBrowserController
instead of HostedAppBrowserController.

Bug: 966290
Change-Id: I2cdf4bc8161e263838d22fc84ba793174eef0db4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2056163Reviewed-by: Alan Cutter <alancutter@chromium.org>
Commit-Queue: Eric Willigers <ericwilligers@chromium.org>
Cr-Commit-Position: refs/heads/master@{#741324}

chrome/common/chrome_features.cc

@@ -260,7 +260,7 @@ const base::Feature kDesktopPWAsTabStrip{"DesktopPWAsTabStrip",
 // TODO(crbug.com/877898): Enable and delete this feature flag before
 // kDesktopPWAsWithoutExtensions launch.
 const base::Feature kDesktopPWAsUnifiedUiController{
-    "DesktopPWAsUnifiedUiController", base::FEATURE_DISABLED_BY_DEFAULT};
+    "DesktopPWAsUnifiedUiController", base::FEATURE_ENABLED_BY_DEFAULT};
 
 // Enables or disables use of new Desktop PWAs launch manager by
 // extensions-based bookmark apps. (Note that Bookmark apps not based