[Android WebView] Implement Ubercomp for Render Thread support

android_webview/lib/main/aw_main_delegate.cc

Index: android_webview/lib/main/aw_main_delegate.cc
diff --git a/android_webview/lib/main/aw_main_delegate.cc b/android_webview/lib/main/aw_main_delegate.cc
index a71c0a6ed86182f07d234af22c9acb566ce38227..db3d5ac788a5d56dc4dc06801367ecb2a218f90f 100644
--- a/android_webview/lib/main/aw_main_delegate.cc
+++ b/android_webview/lib/main/aw_main_delegate.cc
@@ -8,6 +8,7 @@
 #include "android_webview/browser/browser_view_renderer.h"
 #include "android_webview/browser/gpu_memory_buffer_factory_impl.h"
 #include "android_webview/browser/scoped_allow_wait_for_legacy_web_view_api.h"
+#include "android_webview/common/aw_switches.h"
 #include "android_webview/lib/aw_browser_dependency_factory_impl.h"
 #include "android_webview/native/aw_geolocation_permission_context.h"
 #include "android_webview/native/aw_quota_manager_bridge_impl.h"
@@ -66,6 +67,13 @@ bool AwMainDelegate::BasicStartupComplete(int* exit_code) {
   // Not yet supported in single-process mode.
   cl->AppendSwitch(switches::kDisableSharedWorkers);
 
+  if (!switches::UbercompEnabled()) {
+    cl->AppendSwitch(switches::kDisableDelegatedRenderer);
+  } else {
+    cl->AppendSwitch(switches::kDisableAccelerated2dCanvas);
+    cl->AppendSwitch(switches::kDisableExperimentalWebGL);
+  }
+
 
   // File system API not supported (requires some new API; internal bug 6930981)
   cl->AppendSwitch(switches::kDisableFileSystem);