[Android] Conditionally enable M text selection features

content/browser/android/content_startup_flags.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/android/content_startup_flags.h"
 
 #include "base/android/build_info.h"
 #include "base/base_switches.h"
 #include "base/command_line.h"
 #include "base/logging.h"
@@ skipping 45 matching lines @@
     parsed_command_line->AppendSwitch(switches::kSingleProcess);
   }
 
   parsed_command_line->AppendSwitch(cc::switches::kEnableBeginFrameScheduling);
 
   parsed_command_line->AppendSwitch(switches::kEnablePinch);
   parsed_command_line->AppendSwitch(switches::kEnableOverlayFullscreenVideo);
   parsed_command_line->AppendSwitch(switches::kEnableOverlayScrollbar);
   parsed_command_line->AppendSwitch(switches::kValidateInputEventStream);
 
+  // TODO(jdduke): Use the proper SDK version when available, crbug.com/466749.
+  if (base::android::BuildInfo::GetInstance()->sdk_int() >
+      base::android::SDK_VERSION_LOLLIPOP_MR1) {
+    parsed_command_line->AppendSwitch(switches::kEnableLongpressDragSelection);
+    parsed_command_line->AppendSwitchASCII(
+        switches::kTouchTextSelectionStrategy, "direction");
+  }
+
   // There is no software fallback on Android, so don't limit GPU crashes.
   parsed_command_line->AppendSwitch(switches::kDisableGpuProcessCrashLimit);
 
   // On legacy low-memory devices the behavior has not been studied with regard
   // to having an extra process with similar priority as the foreground renderer
   // and given that the system will often be looking for a process to be killed
   // on such systems.
   if (base::SysInfo::IsLowEndDevice())
     parsed_command_line->AppendSwitch(switches::kInProcessGPU);
 
@@ skipping 21 matching lines @@
   }
 
   cc::LayerSettings layer_settings;
   if (parsed_command_line->HasSwitch(
           switches::kEnableAndroidCompositorAnimationTimelines))
     layer_settings.use_compositor_animation_timelines = true;
   Compositor::SetLayerSettings(layer_settings);
 }
 
 }  // namespace content