Plumb gesture source value through Blink.

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

Index: third_party/WebKit/Source/web/tests/VisualViewportTest.cpp
diff --git a/third_party/WebKit/Source/web/tests/VisualViewportTest.cpp b/third_party/WebKit/Source/web/tests/VisualViewportTest.cpp
index 75682ebad9b8c29359bc01bbd6fb1513359ab15c..71a627cfb3c94f9cec86e2cd7e05ca55821b7498 100644
--- a/third_party/WebKit/Source/web/tests/VisualViewportTest.cpp
+++ b/third_party/WebKit/Source/web/tests/VisualViewportTest.cpp
@@ -1612,7 +1612,7 @@ TEST_P(ParameterizedVisualViewportTest, SlowScrollAfterImplScroll)
         IntPoint(0, 0),
         IntPoint(0, 0),
         IntSize(5, 5),
-        0, PlatformEvent::NoModifiers);
+        0, PlatformEvent::NoModifiers, PlatformGestureSourceUninitialized);

[tdresser, 2015/10/14 15:14:20]

I'd like us to be able to assert throughout the codebase that this is never
uninitialized, so let's not use uninitialized in tests.

[wjmaclean, 2015/10/14 15:55:09]

Done.

     gsu.setScrollGestureData(-50, -60, 1, 1, false, false, -1 /* null plugin id */);
 
     frame()->eventHandler().handleGestureEvent(gsu);
@@ -1738,6 +1738,7 @@ TEST_P(ParameterizedVisualViewportTest, PinchZoomGestureScrollsVisualViewportOnl
 
     WebGestureEvent pinchUpdate;
     pinchUpdate.type = WebInputEvent::GesturePinchUpdate;
+    pinchUpdate.sourceDevice = WebGestureDeviceTouchpad;
     pinchUpdate.x = 100;
     pinchUpdate.y = 100;
     pinchUpdate.data.pinchUpdate.scale = 2;