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

adb/Android.bp

@@ -24,7 +24,6 @@ cc_defaults {
         "-Wno-missing-field-initializers",
         "-Wvla",
     ],
-    rtti: true,
 
     use_version_lib: true,
 

adb/transport.cpp

@@ -1305,11 +1305,7 @@ void register_usb_transport(usb_handle* usb, const char* serial, const char* dev
 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

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 @@ class atransport {
         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 @@ class atransport {
     // 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_;
 

adb/transport_usb.cpp

@@ -180,6 +180,7 @@ void init_usb_transport(atransport* t, usb_handle* h) {
     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) {