Add SF side tunnel mode listener

This CL adds a TunnelModeStateReporter, which monitors if there are
any layers with a sideband stream in SurfaceFlinger. If any of the
layers have a sideband stream, it informs all the registered listeners
that tunnel mode is enabled. When no layers have a sideband stream, it
notifies the listeners that tunnel mode is disabled.

Bug: 171457637
Test: atest TunnelModeStateListenerTest
Test: atest TunnelModeStateReporterTest
Change-Id: Ie54b34dbd9b6253d7142e9b0f690c8469374604d
diff --git a/libs/gui/ISurfaceComposer.cpp b/libs/gui/ISurfaceComposer.cpp
index 53721cf..71e18a9 100644
--- a/libs/gui/ISurfaceComposer.cpp
+++ b/libs/gui/ISurfaceComposer.cpp
@@ -824,6 +824,36 @@
         return error;
     }
 
+    virtual status_t addTunnelModeEnabledListener(
+            const sp<gui::ITunnelModeEnabledListener>& listener) {
+        Parcel data, reply;
+        SAFE_PARCEL(data.writeInterfaceToken, ISurfaceComposer::getInterfaceDescriptor());
+        SAFE_PARCEL(data.writeStrongBinder, IInterface::asBinder(listener));
+
+        const status_t error =
+                remote()->transact(BnSurfaceComposer::ADD_TUNNEL_MODE_ENABLED_LISTENER, data,
+                                   &reply);
+        if (error != NO_ERROR) {
+            ALOGE("addTunnelModeEnabledListener: Failed to transact");
+        }
+        return error;
+    }
+
+    virtual status_t removeTunnelModeEnabledListener(
+            const sp<gui::ITunnelModeEnabledListener>& listener) {
+        Parcel data, reply;
+        SAFE_PARCEL(data.writeInterfaceToken, ISurfaceComposer::getInterfaceDescriptor());
+        SAFE_PARCEL(data.writeStrongBinder, IInterface::asBinder(listener));
+
+        const status_t error =
+                remote()->transact(BnSurfaceComposer::REMOVE_TUNNEL_MODE_ENABLED_LISTENER, data,
+                                   &reply);
+        if (error != NO_ERROR) {
+            ALOGE("removeTunnelModeEnabledListener: Failed to transact");
+        }
+        return error;
+    }
+
     status_t setDesiredDisplayModeSpecs(const sp<IBinder>& displayToken,
                                         ui::DisplayModeId defaultMode, bool allowGroupSwitching,
                                         float primaryRefreshRateMin, float primaryRefreshRateMax,
@@ -1740,6 +1770,26 @@
             }
             return removeFpsListener(listener);
         }
+        case ADD_TUNNEL_MODE_ENABLED_LISTENER: {
+            CHECK_INTERFACE(ISurfaceComposer, data, reply);
+            sp<gui::ITunnelModeEnabledListener> listener;
+            status_t result = data.readNullableStrongBinder(&listener);
+            if (result != NO_ERROR) {
+                ALOGE("addTunnelModeEnabledListener: Failed to read listener");
+                return result;
+            }
+            return addTunnelModeEnabledListener(listener);
+        }
+        case REMOVE_TUNNEL_MODE_ENABLED_LISTENER: {
+            CHECK_INTERFACE(ISurfaceComposer, data, reply);
+            sp<gui::ITunnelModeEnabledListener> listener;
+            status_t result = data.readNullableStrongBinder(&listener);
+            if (result != NO_ERROR) {
+                ALOGE("removeTunnelModeEnabledListener: Failed to read listener");
+                return result;
+            }
+            return removeTunnelModeEnabledListener(listener);
+        }
         case SET_DESIRED_DISPLAY_MODE_SPECS: {
             CHECK_INTERFACE(ISurfaceComposer, data, reply);
             sp<IBinder> displayToken = data.readStrongBinder();