Robustification of the echo suppression behavior during headset usage.

This CL robustifies the echo removal behavior when headsets are used.
In particular it:
-Introduces a secondary, more refined alignment when no alignment can
be found using the delay estimator.
-Changes decision logic for when to use the linear filter output.
-Changes the decision logic for when to be transparent.
-Changes the way that the transparent mode works.
-Makes the nonlinear mode less aggressive.
-Removes the detector for non-audible echoes.
-Makes the attenuation when there are signals with strong narrowband
characteristics more mild in scenarios with low render.

Furthermore the CL:
-Removes the input of external echo leakage information.


Bug: webrtc:9047,chromium:824111,webrtc:8314,webrtc:8671,webrtc:5201,webrtc:5919
Change-Id: Ied1fe0c0a35d3c31b47606ed2db319a73644d406
Reviewed-on: https://webrtc-review.googlesource.com/60866
Commit-Queue: Per Åhgren <peah@webrtc.org>
Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22548}

modules/audio_processing/aec3/render_delay_buffer_unittest.cc

@@ -75,12 +75,14 @@ TEST(RenderDelayBuffer, SetDelay) {
   EchoCanceller3Config config;
   std::unique_ptr<RenderDelayBuffer> delay_buffer(
       RenderDelayBuffer::Create(config, 1));
-  ASSERT_FALSE(delay_buffer->Delay());
-  for (size_t delay = config.delay.min_echo_path_delay_blocks + 1; delay < 20;
-       ++delay) {
-    delay_buffer->SetDelay(delay);
-    ASSERT_TRUE(delay_buffer->Delay());
-    EXPECT_EQ(delay, *delay_buffer->Delay());
+  ASSERT_TRUE(delay_buffer->Delay());
+  delay_buffer->Reset();
+  size_t initial_internal_delay = config.delay.min_echo_path_delay_blocks +
+                                  config.delay.api_call_jitter_blocks;
+  for (size_t delay = initial_internal_delay;
+       delay < initial_internal_delay + 20; ++delay) {
+    ASSERT_TRUE(delay_buffer->SetDelay(delay));
+    EXPECT_EQ(delay, delay_buffer->Delay());
   }
 }