Move synchronous compositor into content/browser

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 d153e2e275ed72a015a58a43104639a52e6334ea..f8fca01235f7f5b07fe86087f4dbf9d223d3809e 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -464,11 +464,6 @@ const char kForceCompositingMode[]          = "force-compositing-mode";
 // via field trials.
 const char kDisableForceCompositingMode[]   = "disable-force-compositing-mode";
 
-// Enable the synchronous renderer compositor API. See
-// ContentRendererClient::DidCreateSynchronousCompositor()
-const char kEnableSynchronousRendererCompositor[] =
-    "enable-synchronous-renderer-compositor";
-
 // Some field trials may be randomized in the browser, and the randomly selected
 // outcome needs to be propagated to the renderer. For instance, this is used
 // to modify histograms recorded in the renderer, or to get the renderer to