Resize only the virtual viewport when the OSK triggers a resize.

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 b87df7f8f2d4a75c01367d7858920e4ec9fd1d76..ca4d280b81bcfd1acfe864b1da8e9897c9e6a57e 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -929,6 +929,9 @@ const char kRemoteDebuggingSocketName[]     = "remote-debugging-socket-name";
 // Block ChildProcessMain thread of the renderer's ChildProcessService until a
 // Java debugger is attached.
 const char kRendererWaitForJavaDebugger[] = "renderer-wait-for-java-debugger";
+
+// Enables overscrolling for the OSK on Android.
+const char kEnableOSKOverscroll[]               = "enable-osk-overscroll";
 #endif
 
 // Enable the aggressive flushing of DOM Storage to minimize data loss.