Drop frontbuffers with ui-use-gpu-process, synchronized with browser, decoupled from backbuffer dro…

content/public/common/content_switches.cc

Index: content/public/common/content_switches.cc
diff --git a/content/public/common/content_switches.cc b/content/public/common/content_switches.cc
index 0d3aac4972ec81896296536ba91103d40bdc55c0..3a54005963929280f83f5e7debc78d661f176f43 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -303,6 +303,10 @@ const char kEnableOriginBoundCerts[]  = "enable-origin-bound-certs";
 // Enables partial swaps in the WK compositor on platforms that support it.
 const char kEnablePartialSwap[]             = "enable-partial-swap";
 
+// Enables UI releasing handle to front surface for background tabs on platforms
+// that support it.
+const char kEnableUIReleaseFrontSurface[] = "enable-ui-release-front-surface";
+
 // Enables touch-screen pinch gestures.
 const char kEnablePinch[]                   = "enable-pinch";