Allow extracting the linear AEC output

This CL enables extracting the linear AEC output,
allowing for more straightforward
testing/development.

Bug: b/140823178
Change-Id: I14f7934008d87066b35500466cb6e6d96f811688
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/153672
Commit-Queue: Per Åhgren <peah@webrtc.org>
Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29789}
diff --git a/modules/audio_processing/aec3/echo_remover_unittest.cc b/modules/audio_processing/aec3/echo_remover_unittest.cc
index 15d0913..d79993a 100644
--- a/modules/audio_processing/aec3/echo_remover_unittest.cc
+++ b/modules/audio_processing/aec3/echo_remover_unittest.cc
@@ -73,9 +73,9 @@
           render_buffer->Insert(render);
           render_buffer->PrepareCaptureProcessing();
 
-          remover->ProcessCapture(echo_path_variability,
-                                  k % 2 == 0 ? true : false, delay_estimate,
-                                  render_buffer->GetRenderBuffer(), &capture);
+          remover->ProcessCapture(
+              echo_path_variability, k % 2 == 0 ? true : false, delay_estimate,
+              render_buffer->GetRenderBuffer(), nullptr, &capture);
         }
       }
     }
@@ -107,10 +107,10 @@
                                    1, std::vector<float>(kBlockSize - 1, 0.f)));
     EchoPathVariability echo_path_variability(
         false, EchoPathVariability::DelayAdjustment::kNone, false);
-    EXPECT_DEATH(
-        remover->ProcessCapture(echo_path_variability, false, delay_estimate,
-                                render_buffer->GetRenderBuffer(), &capture),
-        "");
+    EXPECT_DEATH(remover->ProcessCapture(
+                     echo_path_variability, false, delay_estimate,
+                     render_buffer->GetRenderBuffer(), nullptr, &capture),
+                 "");
   }
 }
 
@@ -131,10 +131,10 @@
                                         std::vector<float>(kBlockSize, 0.f)));
     EchoPathVariability echo_path_variability(
         false, EchoPathVariability::DelayAdjustment::kNone, false);
-    EXPECT_DEATH(
-        remover->ProcessCapture(echo_path_variability, false, delay_estimate,
-                                render_buffer->GetRenderBuffer(), &capture),
-        "");
+    EXPECT_DEATH(remover->ProcessCapture(
+                     echo_path_variability, false, delay_estimate,
+                     render_buffer->GetRenderBuffer(), nullptr, &capture),
+                 "");
   }
 }
 
@@ -147,10 +147,10 @@
       RenderDelayBuffer::Create(EchoCanceller3Config(), 16000, 1));
   EchoPathVariability echo_path_variability(
       false, EchoPathVariability::DelayAdjustment::kNone, false);
-  EXPECT_DEATH(
-      remover->ProcessCapture(echo_path_variability, false, delay_estimate,
-                              render_buffer->GetRenderBuffer(), nullptr),
-      "");
+  EXPECT_DEATH(remover->ProcessCapture(
+                   echo_path_variability, false, delay_estimate,
+                   render_buffer->GetRenderBuffer(), nullptr, nullptr),
+               "");
 }
 
 #endif
@@ -222,7 +222,8 @@
           render_buffer->PrepareCaptureProcessing();
 
           remover->ProcessCapture(echo_path_variability, false, delay_estimate,
-                                  render_buffer->GetRenderBuffer(), &y);
+                                  render_buffer->GetRenderBuffer(), nullptr,
+                                  &y);
 
           if (k > kNumBlocksToProcess / 2) {
             output_energy = std::inner_product(y[0][0].begin(), y[0][0].end(),