Makes NativeViewport send OnBoundsChanged() after widget available

mojo/public/cpp/bindings/callback.h

Index: mojo/public/cpp/bindings/callback.h
diff --git a/mojo/public/cpp/bindings/callback.h b/mojo/public/cpp/bindings/callback.h
index 8d39b0231da927cdd068d3a19e5e3f3d94cb24ad..9922ea306d5aeda0324f9b78cc515a99847de4c1 100644
--- a/mojo/public/cpp/bindings/callback.h
+++ b/mojo/public/cpp/bindings/callback.h
@@ -47,6 +47,10 @@ class Callback<void()> {
     return !sink_.get();
   }
 
+  void reset() {
+    sink_.reset();
+  }
+
  private:
   template <typename Sink>
   struct Adapter : public Runnable {
@@ -88,6 +92,10 @@ class Callback<void(A1)> {
     return !sink_.get();
   }
 
+  void reset() {
+    sink_.reset();
+  }
+
  private:
   template <typename Sink>
   struct Adapter : public Runnable {
@@ -136,6 +144,10 @@ class Callback<void(A1, A2)> {
     return !sink_.get();
   }
 
+  void reset() {
+    sink_.reset();
+  }
+
  private:
   template <typename Sink>
   struct Adapter : public Runnable {
@@ -190,6 +202,10 @@ class Callback<void(A1, A2, A3)> {
     return !sink_.get();
   }
 
+  void reset() {
+    sink_.reset();
+  }
+
  private:
   template <typename Sink>
   struct Adapter : public Runnable {
@@ -249,6 +265,10 @@ class Callback<void(A1, A2, A3, A4)> {
     return !sink_.get();
   }
 
+  void reset() {
+    sink_.reset();
+  }
+
  private:
   template <typename Sink>
   struct Adapter : public Runnable {
@@ -313,6 +333,10 @@ class Callback<void(A1, A2, A3, A4, A5)> {
     return !sink_.get();
   }
 
+  void reset() {
+    sink_.reset();
+  }
+
  private:
   template <typename Sink>
   struct Adapter : public Runnable {
@@ -383,6 +407,10 @@ class Callback<void(A1, A2, A3, A4, A5, A6)> {
     return !sink_.get();
   }
 
+  void reset() {
+    sink_.reset();
+  }
+
  private:
   template <typename Sink>
   struct Adapter : public Runnable {
@@ -458,6 +486,10 @@ class Callback<void(A1, A2, A3, A4, A5, A6, A7)> {
     return !sink_.get();
   }
 
+  void reset() {
+    sink_.reset();
+  }
+
  private:
   template <typename Sink>
   struct Adapter : public Runnable {