Chromium side plumbing for enabling fixed root background compositing.

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 4112461a4b0933377c50edf7564e605de41c92b3..3476edc7dfaac0a41b6b4ec4383a4764351a025a 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -641,7 +641,7 @@ const char kEnableAcceleratedOverflowScroll[] =
     "enable-accelerated-overflow-scroll";
 
 // Disables accelerated compositing for overflow scroll.
-extern const char kDisableAcceleratedOverflowScroll[] =
+const char kDisableAcceleratedOverflowScroll[] =
     "disable-accelerated-overflow-scroll";
 
 // Enables accelerated compositing for scrollable frames for accelerated
@@ -856,4 +856,11 @@ const char kEnableWebPInAcceptHeader[] = "enable-webp-in-accept-header";
 // Enables WebGL extensions not yet approved by the community.
 const char kEnableWebGLDraftExtensions[] = "enable-webgl-draft-extensions";
 
+// Enables/disables accelerated compositing for backgrounds of root layers with
+// background-attachment: fixed. Requires kForceCompositingMode.
+const char kDisableAcceleratedFixedRootBackground[] =
+    "disable-accelerated-fixed-root-background";
+const char kEnableAcceleratedFixedRootBackground[] =
+    "enable-accelerated-fixed-root-background";
+
 }  // namespace switches