sync compositor: Remove sync input path

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 ea970343592a4158798124928569760745c743c9..1bd5b0894789cbe44a2a0988d335b491c2686cac 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -957,12 +957,6 @@ const char kRemoteDebuggingSocketName[]     = "remote-debugging-socket-name";
 // Java debugger is attached.
 const char kRendererWaitForJavaDebugger[] = "renderer-wait-for-java-debugger";
 
-// Use synchronous input code path for IPC-synchronous compositing. This is the
-// legacy input code path used by the in-process synchronous compositor.
-// Maintaining this code path in case there are compatibility bugs with the
-// standard async input path. Remove tracked as part of crbug.com/545628.
-const char kSyncInputForSyncCompositor[]    = "sync-input-for-sync-compositor";
-
 // Enables overscrolling for the OSK on Android.
 const char kEnableOSKOverscroll[]               = "enable-osk-overscroll";
 #endif