Add EventForwarder for routing touch events

ui/android/BUILD.gn

Index: ui/android/BUILD.gn
diff --git a/ui/android/BUILD.gn b/ui/android/BUILD.gn
index 2374b2a454f9a68dcf5f7860fa5513209f8b1a50..386a81499419cdff478dcc143cc4d644068bfe63 100644
--- a/ui/android/BUILD.gn
+++ b/ui/android/BUILD.gn
@@ -23,6 +23,8 @@ component("android") {
     "edge_effect_base.h",
     "edge_effect_l.cc",
     "edge_effect_l.h",
+    "event_handler.cc",
+    "event_handler.h",
     "overscroll_glow.cc",
     "overscroll_glow.h",
     "overscroll_refresh.cc",
@@ -42,6 +44,8 @@ component("android") {
     "ui_android_jni_registrar.h",
     "view_android.cc",
     "view_android.h",
+    "view_client.cc",
+    "view_client.h",
     "window_android.cc",
     "window_android.h",
     "window_android_compositor.h",
@@ -58,7 +62,9 @@ component("android") {
     "//cc/surfaces",
     "//cc/surfaces:surface_id",
     "//skia",
+    "//ui/base",
     "//ui/display",
+    "//ui/events",
     "//ui/gfx",
     "//ui/gfx/geometry",
     "//url",
@@ -81,6 +87,7 @@ static_library("test_support") {
 generate_jni("ui_android_jni_headers") {
   sources = [
     "java/src/org/chromium/ui/OverscrollRefreshHandler.java",
+    "java/src/org/chromium/ui/base/EventHandler.java",
     "java/src/org/chromium/ui/base/ViewAndroidDelegate.java",
     "java/src/org/chromium/ui/base/WindowAndroid.java",
     "java/src/org/chromium/ui/display/DisplayAndroidManager.java",
@@ -172,9 +179,11 @@ android_library("ui_java") {
     "java/src/org/chromium/ui/base/AndroidPermissionDelegate.java",
     "java/src/org/chromium/ui/base/Clipboard.java",
     "java/src/org/chromium/ui/base/DeviceFormFactor.java",
+    "java/src/org/chromium/ui/base/EventHandler.java",
     "java/src/org/chromium/ui/base/LocalizationUtils.java",
     "java/src/org/chromium/ui/base/ResourceBundle.java",
     "java/src/org/chromium/ui/base/SelectFileDialog.java",
+    "java/src/org/chromium/ui/base/SPenSupport.java",
     "java/src/org/chromium/ui/base/TouchDevice.java",
     "java/src/org/chromium/ui/base/ViewAndroidDelegate.java",
     "java/src/org/chromium/ui/base/WindowAndroid.java",