gesture recognizer: Recognizer rotation gestures.

ash/wm/gestures/system_pinch_handler.cc

Index: ash/wm/gestures/system_pinch_handler.cc
diff --git a/ash/wm/gestures/system_pinch_handler.cc b/ash/wm/gestures/system_pinch_handler.cc
index d974addc6ba1fd2669a03a60fca1c96704242a5f..1feed30516627daf3738040840ec268ef645ae52 100644
--- a/ash/wm/gestures/system_pinch_handler.cc
+++ b/ash/wm/gestures/system_pinch_handler.cc
@@ -4,6 +4,8 @@
 
 #include "ash/wm/gestures/system_pinch_handler.h"
 
+#include <math.h>
+
 #include "ash/launcher/launcher.h"
 #include "ash/screen_ash.h"
 #include "ash/shell.h"
@@ -48,6 +50,8 @@ SystemGestureStatus SystemPinchHandler::ProcessGestureEvent(
       if (event.details().touch_points() > kSystemGesturePoints)
         break;
 
+      target_->SetTransform(ui::Transform());
+
       if (phantom_state_ == PHANTOM_WINDOW_MAXIMIZED) {
         if (!wm::IsWindowMaximized(target_) &&
             !wm::IsWindowFullscreen(target_))
@@ -74,6 +78,12 @@ SystemGestureStatus SystemPinchHandler::ProcessGestureEvent(
           GetPhantomWindowScreenBounds(target_, event.location());
       if (phantom_state_ != PHANTOM_WINDOW_NORMAL || phantom_.IsShowing())
         phantom_.Show(bounds, NULL);
+
+      float rotation = event.details().rotation();
+      LOG(ERROR) << "Rotation: " << rotation;
+      ui::Transform transform = target_->layer()->transform();
+      transform.ConcatRotate(-rotation * 180 / M_PI);
+      target_->SetTransform(transform);
       break;
     }