Re-enable unified gesture detector.

Enabled here: https://codereview.chromium.org/315713002/
Disable here: https://codereview.chromium.org/312303003/

BUG=332418
TEST=GestureRecognizerTest.*

Review URL: https://codereview.chromium.org/318853005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@276742 0039d316-1c4b-4281-b951-d872f2087c98

tools/valgrind/gtest_exclude/ash_unittests.gtest-memcheck.txt

@@ -2,3 +2,5 @@
 AutoclickTest.UserInputCancelsAutoclick
 # http://crbug.com/337149
 AutoclickTest.SynthesizedMouseMovesIgnored
+# http://crbug.com/383384
+SystemGestureEventFilterTest.TwoFingerDragDelayed

tools/valgrind/gtest_exclude/aura_unittests.gtest-memcheck.txt

+# http://crbug.com/383386
+WindowTest.TouchCaptureDoesntCancelCapturedTouches

ui/events/gestures/gesture_recognizer_impl.cc

@@ -69,14 +69,14 @@ GestureProviderAura* CreateGestureProvider(GestureProviderAuraClient* client) {
 // GestureRecognizerImpl, public:
 
 GestureRecognizerImpl::GestureRecognizerImpl() {
-  // Default to not using the unified gesture detector.
+  // Default to using the unified gesture detector.
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
   const std::string unified_gd_enabled_switch =
       command_line.HasSwitch(switches::kUnifiedGestureDetector) ?
       command_line.GetSwitchValueASCII(switches::kUnifiedGestureDetector) :
       switches::kUnifiedGestureDetectorAuto;
 
-  const bool kUseUnifiedGestureDetectorByDefault = false;
+  const bool kUseUnifiedGestureDetectorByDefault = true;
   if (unified_gd_enabled_switch.empty() ||
       unified_gd_enabled_switch == switches::kUnifiedGestureDetectorEnabled) {
     use_unified_gesture_detector_ = true;