Implements PrintBrowser mode.

third_party/WebKit/Source/platform/RuntimeEnabledFeatures.json5

Index: third_party/WebKit/Source/platform/RuntimeEnabledFeatures.json5
diff --git a/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.json5 b/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.json5
index f934de098359b77c6dc907b08ba9b5bc19570187..99503f592cad8198986047da7125f630b1d9fb17 100644
--- a/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.json5
+++ b/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.json5
@@ -701,6 +701,9 @@
       name: "PreciseMemoryInfo",
     },
     {
+      name: "PrintBrowser",
+    },
+    {
       name: "PreferredImageRasterBounds",
       settable_from_internals: true,
     },
@@ -805,6 +808,7 @@
     },
     {
       name: "SlimmingPaintV2",
+      implied_by: ["PrintBrowser"],
     },
     {
       name: "SlimmingPaintStrictCullRectClipping",