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

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 1024afcf433519278f4c4d5b2355b0fa5f7c332f..6a7d72224d33ce991800d4ad8d49ddb67d019289 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -676,6 +676,11 @@ const Experiment kExperiments[] = {
      IDS_FLAGS_DISABLE_WEBAUDIO_DESCRIPTION,
      kOsAndroid,
      SINGLE_VALUE_TYPE(switches::kDisableWebAudio)},
+    {"enable-osk-overscroll",
+     IDS_FLAGS_ENABLE_OSK_OVERSCROLL_NAME,
+     IDS_FLAGS_ENABLE_OSK_OVERSCROLL_DESCRIPTION,
+     kOsAndroid,
+     SINGLE_VALUE_TYPE(switches::kEnableOSKOverscroll)},
 #endif
   // Native client is compiled out when DISABLE_NACL is defined.
 #if !defined(DISABLE_NACL)