Send early ShowPress on TapDown when page isn't scrollable/pinchable.

Source/core/page/ChromeClient.h

Index: Source/core/page/ChromeClient.h
diff --git a/Source/core/page/ChromeClient.h b/Source/core/page/ChromeClient.h
index acca8be818e18bfedeae2bb1f16eb8960f81ffc8..34204b01b993f4b79c5f48c57c264678293c07f8 100644
--- a/Source/core/page/ChromeClient.h
+++ b/Source/core/page/ChromeClient.h
@@ -267,6 +267,9 @@ public:
     // Notifies the client a popup was closed.
     virtual void popupClosed(PopupContainer* popupContainer) = 0;
 
+    virtual float minimumPageScaleFactor() const = 0;

[Rick Byers, 2014/02/14 21:27:53]

did aelias@ suggest exposing both of these?  I was expecting something more
specific to pinch being enabled (eg. how does this interact with browser zoom on
desktop which I believe uses page scale factor as well?).  But I defer to
aelias@ here.  This is probably OK too.

[bokan, 2014/02/18 19:59:57]

I think these should instead be isPinchZoomable() (maybe with better name). It's
not immediately clear that "pinch zoom disabled iff minimum == maximum" (i.e.
pinch code could check the user-scale=no setting without consulting min/max).
This would be more explicit.

+    virtual float maximumPageScaleFactor() const = 0;
+
 protected:
     virtual ~ChromeClient() { }
 };