Support dragging texts into Android WebView.

ui/base/ui_base.gyp

Index: ui/base/ui_base.gyp
diff --git a/ui/base/ui_base.gyp b/ui/base/ui_base.gyp
index d092bc1552b8e06d69aa8a5ce1e01e80e1538845..8a7502e54fe1b36ba6effd96c0b61db40968ad45 100644
--- a/ui/base/ui_base.gyp
+++ b/ui/base/ui_base.gyp
@@ -600,7 +600,7 @@
             '../../build/linux/system.gyp:xscrnsaver',
           ],
         }],
-        ['toolkit_views==0', {
+        ['toolkit_views==0 and OS!="android"', {
           'sources!': [
             'dragdrop/drag_drop_types.h',
             'dragdrop/drop_target_event.cc',
@@ -637,6 +637,15 @@
           },
         }],
         ['OS=="android" and use_aura==0', {
+          'sources+': [
+            'dragdrop/drag_drop_types.h',
+            'dragdrop/drop_target_event.cc',
+            'dragdrop/drop_target_event.h',
+            'dragdrop/os_exchange_data.cc',
+            'dragdrop/os_exchange_data.h',
+            'dragdrop/os_exchange_data_provider_android.cc',
+            'dragdrop/os_exchange_data_provider_android.h',
+          ],
           'sources!': [
             'cursor/cursor_android.cc',
             'idle/idle.cc',