修复browser的一些问题

DrissionPage/_base/browser.py

@@ -47,16 +47,15 @@ class Browser(object):
                 self._process_id = i['id']
                 break
 
-        self.run_cdp('Target.setDiscoverTargets')
+        self.run_cdp('Target.setDiscoverTargets', discover=True)
         self._driver.set_listener('Target.targetDestroyed', self._onTargetDestroyed)
 
     def _onTargetDestroyed(self, **kwargs):
         """标签页关闭时执行"""
         tab_id = kwargs['targetId']
         self._dl_mgr.clear_tab_info(tab_id)
-        for k, i in self._frames.items():
-            if i == tab_id:
-                self._frames.pop(k)
+        for item in [(k, i) for k, i in self._frames.items() if i == tab_id]:
+            self._frames.pop(item[0])
 
     def connect_to_page(self):
         """执行与page相关的逻辑"""

DrissionPage/_base/browser.pyi

@@ -50,6 +50,6 @@ class Browser(object):
 
     def connect_to_page(self) -> None: ...
 
-    def _onTargetDestroyed(self, **kwargs): ...
+    def _onTargetDestroyed(self, **kwargs) -> None: ...
 
     def quit(self) -> None: ...

DrissionPage/_units/download_manager.py

@@ -127,9 +127,18 @@ class BrowserDownloadManager(object):
         :param tab_id: 标签页id
         :return: None
         """
-        self._tab_missions.pop(tab_id)
-        self._flags.pop(tab_id)
-        TabDownloadSettings.TABS.pop(tab_id)
+        try:
+            self._tab_missions.pop(tab_id)
+        except KeyError:
+            pass
+        try:
+            self._flags.pop(tab_id)
+        except KeyError:
+            pass
+        try:
+            TabDownloadSettings.TABS.pop(tab_id)
+        except KeyError:
+            pass
 
     def _onDownloadWillBegin(self, **kwargs):
         """用于获取弹出新标签页触发的下载任务"""