Add API to WebFrame to enable/disable caret.

Source/web/WebFrameImpl.cpp

Index: Source/web/WebFrameImpl.cpp
diff --git a/Source/web/WebFrameImpl.cpp b/Source/web/WebFrameImpl.cpp
index 0d69563f87d877860196d43002d219f0a2b0c2b2..639a06a2ed3d6a72f9c4a8c24ee1cd8df6b03878 100644
--- a/Source/web/WebFrameImpl.cpp
+++ b/Source/web/WebFrameImpl.cpp
@@ -1366,6 +1366,11 @@ void WebFrameImpl::moveCaretSelection(const WebPoint& point)
         frame()->selection()->moveTo(position, UserTriggered);
 }
 
+void WebFrameImpl::setCaretEnabled(bool enable)
+{
+    frame()->selection()->setCaretVisible(enable);

[abarth-chromium, 2013/08/12 18:40:34]

Is there a reason to use a different name in the API and the implementation? 
Perhaps we should use the name "setCaretVisible" in the API...

[varunjain, 2013/08/12 21:43:40]

No particular reason. Changed.

+}
+
 VisiblePosition WebFrameImpl::visiblePositionForWindowPoint(const WebPoint& point)
 {
     FloatPoint unscaledPoint(point);