Added plumbing for the availablechange event from Blink to WebPresentationClient.

public/platform/WebPresentationClient.h

Index: public/platform/WebPresentationClient.h
diff --git a/public/platform/WebPresentationClient.h b/public/platform/WebPresentationClient.h
new file mode 100644
index 0000000000000000000000000000000000000000..91ce38583a6bf5d8e4bbe869d149c700916a5a3a
--- /dev/null
+++ b/public/platform/WebPresentationClient.h
@@ -0,0 +1,24 @@
+// Copyright (c) 2015 The Chromium Authors. All rights reserved.

[Peter Beverloo, 2015/01/07 14:29:09]

nit: no (c).

[whywhat, 2015/01/07 16:22:16]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef WebPresentationClient_h
+#define WebPresentationClient_h
+
+namespace blink {
+
+class WebPresentationController;
+
+class WebPresentationClient {

[Peter Beverloo, 2015/01/07 14:29:09]

This is an API class, so please add documentation comment blocks to what the
expected behavior is.

[whywhat, 2015/01/07 16:22:16]

Done.

+public:
+    virtual ~WebPresentationClient() { }
+
+    virtual void setController(WebPresentationController*) = 0;
+
+    virtual void addDeviceAvailabilityListener() = 0;
+    virtual void removeDeviceAvailabilityListener() = 0;
+};
+
+} // namespace blink
+
+#endif // WebPresentationClient_h