Adding handlers for user gesture callbacks.

Source/platform/UserGestureIndicator.cpp

Index: Source/platform/UserGestureIndicator.cpp
diff --git a/Source/platform/UserGestureIndicator.cpp b/Source/platform/UserGestureIndicator.cpp
index 03d219537a755790da17f7bf8602c9a560633c6b..eed12c688dc584544ac5533a9ab61ea712ab81fb 100644
--- a/Source/platform/UserGestureIndicator.cpp
+++ b/Source/platform/UserGestureIndicator.cpp
@@ -29,6 +29,7 @@
 #include "wtf/Assertions.h"
 #include "wtf/CurrentTime.h"
 #include "wtf/MainThread.h"
+#include "wtf/Vector.h"
 
 namespace WebCore {
 
@@ -112,6 +113,7 @@ static bool isDefinite(ProcessingUserGestureState state)
 
 ProcessingUserGestureState UserGestureIndicator::s_state = DefinitelyNotProcessingUserGesture;
 UserGestureIndicator* UserGestureIndicator::s_topmostIndicator = 0;
+UserGestureHandler* UserGestureIndicator::s_handler = 0;
 
 UserGestureIndicator::UserGestureIndicator(ProcessingUserGestureState state)
     : m_previousState(s_state)
@@ -131,10 +133,17 @@ UserGestureIndicator::UserGestureIndicator(ProcessingUserGestureState state)
         s_state = state;
     }
 
-    if (state == DefinitelyProcessingNewUserGesture)
+    bool onGesture = false;

[abarth-chromium, 2013/11/26 19:36:37]

Can we name this something that sounds like a boolean?  Maybe
shouldNotifyHandler?

[jww, 2013/11/26 20:11:55]

Done.

+    if (state == DefinitelyProcessingNewUserGesture) {
         static_cast<GestureToken*>(m_token.get())->addGesture();
-    else if (state == DefinitelyProcessingUserGesture && s_topmostIndicator == this)
+        onGesture = true;
+    } else if (state == DefinitelyProcessingUserGesture && s_topmostIndicator == this) {
         static_cast<GestureToken*>(m_token.get())->addGesture();
+        onGesture = true;
+    }
+
+    if (onGesture && s_handler)
+        s_handler->onGesture();
     ASSERT(isDefinite(s_state));
 }
 
@@ -158,6 +167,9 @@ UserGestureIndicator::UserGestureIndicator(PassRefPtr<UserGestureToken> token)
             }
         }
         s_state = DefinitelyProcessingUserGesture;
+
+        if (s_handler)
+            s_handler->onGesture();
     }
 
     ASSERT(isDefinite(s_state));
@@ -194,6 +206,11 @@ UserGestureToken* UserGestureIndicator::currentToken()
     return s_topmostIndicator->m_token.get();
 }
 
+void UserGestureIndicator::setHandler(UserGestureHandler* handler)
+{
+    s_handler = handler;
+}
+
 UserGestureIndicatorDisabler::UserGestureIndicatorDisabler()
     : m_savedState(UserGestureIndicator::s_state)
     , m_savedIndicator(UserGestureIndicator::s_topmostIndicator)