Adds mock bitrate allocator.

This is used to allow mocking in tests in later CLs.

Bug: None
Change-Id: Id610471efb4a86c903530585dd4ee2fa1d1ea5bc
Reviewed-on: https://webrtc-review.googlesource.com/70880
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22941}

call/BUILD.gn

@@ -370,7 +370,17 @@ if (rtc_include_tests) {
       "../test:test_support",
     ]
   }
+  rtc_source_set("mock_bitrate_allocator") {
+    testonly = true
 
+    sources = [
+      "test/mock_bitrate_allocator.h",
+    ]
+    deps = [
+      ":bitrate_allocator",
+      "//test:test_support",
+    ]
+  }
   rtc_source_set("mock_call_interfaces") {
     testonly = true
 

call/bitrate_allocator.h

@@ -67,10 +67,22 @@ struct MediaStreamAllocationConfig {
   bool has_packet_feedback;
 };
 
+// Interface used for mocking
+class BitrateAllocatorInterface {
+ public:
+  virtual void AddObserver(BitrateAllocatorObserver* observer,
+                           MediaStreamAllocationConfig config) = 0;
+  virtual void RemoveObserver(BitrateAllocatorObserver* observer) = 0;
+  virtual int GetStartBitrate(BitrateAllocatorObserver* observer) = 0;
+
+ protected:
+  virtual ~BitrateAllocatorInterface() = default;
+};
+
 // Usage: this class will register multiple RtcpBitrateObserver's one at each
 // RTCP module. It will aggregate the results and run one bandwidth estimation
 // and push the result to the encoders via BitrateAllocatorObserver(s).
-class BitrateAllocator {
+class BitrateAllocator : public BitrateAllocatorInterface {
  public:
   // Used to get notified when send stream limits such as the minimum send
   // bitrate and max padding bitrate is changed.
@@ -82,7 +94,7 @@ class BitrateAllocator {
                                            bool has_packet_feedback) = 0;
 
    protected:
-    virtual ~LimitObserver() {}
+    virtual ~LimitObserver() = default;
   };
 
   explicit BitrateAllocator(LimitObserver* limit_observer);
@@ -98,15 +110,15 @@ class BitrateAllocator {
   // |observer| updates bitrates if already in use.
   // |config| is the configuration to use for allocation.
   void AddObserver(BitrateAllocatorObserver* observer,
-                   MediaStreamAllocationConfig config);
+                   MediaStreamAllocationConfig config) override;
 
   // Removes a previously added observer, but will not trigger a new bitrate
   // allocation.
-  void RemoveObserver(BitrateAllocatorObserver* observer);
+  void RemoveObserver(BitrateAllocatorObserver* observer) override;
 
   // Returns initial bitrate allocated for |observer|. If |observer| is not in
   // the list of added observers, a best guess is returned.
-  int GetStartBitrate(BitrateAllocatorObserver* observer);
+  int GetStartBitrate(BitrateAllocatorObserver* observer) override;
 
   // Sets external allocation strategy. If strategy is not set default WebRTC
   // allocation mechanism will be used. The strategy may be changed during call.

call/test/mock_bitrate_allocator.h

@@ -0,0 +1,27 @@
+/*
+ *  Copyright 2018 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#ifndef CALL_TEST_MOCK_BITRATE_ALLOCATOR_H_
+#define CALL_TEST_MOCK_BITRATE_ALLOCATOR_H_
+
+#include <string>
+
+#include "call/bitrate_allocator.h"
+#include "test/gmock.h"
+
+namespace webrtc {
+class MockBitrateAllocator : public BitrateAllocatorInterface {
+ public:
+  MOCK_METHOD2(AddObserver,
+               void(BitrateAllocatorObserver*, MediaStreamAllocationConfig));
+  MOCK_METHOD1(RemoveObserver, void(BitrateAllocatorObserver*));
+  MOCK_METHOD1(GetStartBitrate, int(BitrateAllocatorObserver*));
+};
+}  // namespace webrtc
+#endif  // CALL_TEST_MOCK_BITRATE_ALLOCATOR_H_