Merge "AudioFlinger: avoid doing balance before downmixing" into tm-d1-dev am: 8edaa192

                void *buffer = mEffectBufferValid ? mEffectBuffer : mSinkBuffer;

                audio_format_t format = mEffectBufferValid ? mEffectBufferFormat : mFormat;

                // Apply mono blending and balancing if the effect buffer is not valid. Otherwise,

                // do these processes after effects are applied.

                if (!mEffectBufferValid) {

                    // mono blend occurs for mixer threads only (not direct or offloaded)

                    // and is handled here if we're going directly to the sink.

                if (requireMonoBlend() && !mEffectBufferValid) {

                    mono_blend(mMixerBuffer, mMixerBufferFormat, mChannelCount, mNormalFrameCount,

                               true /*limit*/);

                    if (requireMonoBlend()) {

                        mono_blend(mMixerBuffer, mMixerBufferFormat, mChannelCount,

                                mNormalFrameCount, true /*limit*/);

                    }

                    if (!hasFastMixer()) {

                        // Balance must take effect after mono conversion.

                        // We do it here if there is no FastMixer.

                    // mBalance detects zero balance within the class for speed (not needed here).

                        // mBalance detects zero balance within the class for speed

                        // (not needed here).

                        mBalance.setBalance(mMasterBalance.load());

                        mBalance.process((float *)mMixerBuffer, mNormalFrameCount);

                    }

                }

                memcpy_by_audio_format(buffer, format, mMixerBuffer, mMixerBufferFormat,

                        mNormalFrameCount * (mixerChannelCount + mHapticChannelCount));