adb: remove incorrect use of RTTI.

We were dynamic_casting to UsbConnection to check for USB connections,
but the actual type was a BlockingConnectionAdapter wrapping a
UsbConnection, with the result that unplugging an inaccessible (due to
permissions) device on Linux wouldn't make the device go away.

Test: manual
Change-Id: Icb4acea5fd3c3baa9691698686213e122e898e4a
diff --git a/adb/Android.bp b/adb/Android.bp
index ae8e386..fd68bc3 100644
--- a/adb/Android.bp
+++ b/adb/Android.bp
@@ -24,7 +24,6 @@
         "-Wno-missing-field-initializers",
         "-Wvla",
     ],
-    rtti: true,
 
     use_version_lib: true,
 
diff --git a/adb/transport.cpp b/adb/transport.cpp
index 8741654..f59a135 100644
--- a/adb/transport.cpp
+++ b/adb/transport.cpp
@@ -1305,11 +1305,7 @@
 void unregister_usb_transport(usb_handle* usb) {
     std::lock_guard<std::recursive_mutex> lock(transport_lock);
     transport_list.remove_if([usb](atransport* t) {
-        auto connection = t->connection();
-        if (auto usb_connection = dynamic_cast<UsbConnection*>(connection.get())) {
-            return usb_connection->handle_ == usb && t->GetConnectionState() == kCsNoPerm;
-        }
-        return false;
+        return t->GetUsbHandle() == usb && t->GetConnectionState() == kCsNoPerm;
     });
 }
 #endif
diff --git a/adb/transport.h b/adb/transport.h
index d593700..790004f 100644
--- a/adb/transport.h
+++ b/adb/transport.h
@@ -37,6 +37,7 @@
 
 #include "adb.h"
 #include "adb_unique_fd.h"
+#include "usb.h"
 
 typedef std::unordered_set<std::string> FeatureSet;
 
@@ -242,6 +243,9 @@
         return connection_;
     }
 
+    void SetUsbHandle(usb_handle* h) { usb_handle_ = h; }
+    usb_handle* GetUsbHandle() { return usb_handle_; }
+
     const TransportId id;
     size_t ref_count = 0;
     bool online = false;
@@ -333,6 +337,9 @@
     // The underlying connection object.
     std::shared_ptr<Connection> connection_ GUARDED_BY(mutex_);
 
+    // USB handle for the connection, if available.
+    usb_handle* usb_handle_ = nullptr;
+
     // A callback that will be invoked when the atransport needs to reconnect.
     ReconnectCallback reconnect_;
 
diff --git a/adb/transport_usb.cpp b/adb/transport_usb.cpp
index c471bf9..2e5918a 100644
--- a/adb/transport_usb.cpp
+++ b/adb/transport_usb.cpp
@@ -180,6 +180,7 @@
     auto connection = std::make_unique<UsbConnection>(h);
     t->SetConnection(std::make_unique<BlockingConnectionAdapter>(std::move(connection)));
     t->type = kTransportUsb;
+    t->SetUsbHandle(h);
 }
 
 int is_adb_interface(int usb_class, int usb_subclass, int usb_protocol) {