Plumb gesture source value through Blink.

third_party/WebKit/Source/web/tests/WebInputEventConversionTest.cpp

Index: third_party/WebKit/Source/web/tests/WebInputEventConversionTest.cpp
diff --git a/third_party/WebKit/Source/web/tests/WebInputEventConversionTest.cpp b/third_party/WebKit/Source/web/tests/WebInputEventConversionTest.cpp
index 3b9a157531d89d8781c190da6fc1e8fe4b6a8c6b..fd22d785fcb76e21bdc10fb9dfeea837f2d062bc 100644
--- a/third_party/WebKit/Source/web/tests/WebInputEventConversionTest.cpp
+++ b/third_party/WebKit/Source/web/tests/WebInputEventConversionTest.cpp
@@ -433,7 +433,7 @@ TEST(WebInputEventConversionTest, InputEventsScaling)
 
     {
         PlatformGestureEvent platformGestureEvent(PlatformEvent::GestureScrollUpdate, IntPoint(10, 12), IntPoint(20, 22), IntSize(25, 27), 0,
-            PlatformEvent::NoModifiers);
+            PlatformEvent::NoModifiers, PlatformGestureSourceTouchscreen);
         platformGestureEvent.setScrollGestureData(30, 32, 40, 42, true, true, -1 /* null plugin id */);
         // FIXME: GestureEvent does not preserve velocityX, velocityY,
         // or preventPropagation. It also fails to scale
@@ -453,6 +453,7 @@ TEST(WebInputEventConversionTest, InputEventsScaling)
         EXPECT_EQ(0, webGestureBuilder.data.scrollUpdate.velocityY);
         EXPECT_TRUE(webGestureBuilder.data.scrollUpdate.inertial);
         EXPECT_FALSE(webGestureBuilder.data.scrollUpdate.preventPropagation);
+        EXPECT_EQ(WebGestureDeviceTouchscreen,  webGestureBuilder.sourceDevice);
     }
 
     {