[DevTools] Fix crash in DevToolsWindow::ActivateContents.

chrome/browser/devtools/devtools_window.cc

Index: chrome/browser/devtools/devtools_window.cc
diff --git a/chrome/browser/devtools/devtools_window.cc b/chrome/browser/devtools/devtools_window.cc
index 5df054678099b1ced62168c885b50e6075dde2b6..5706f4a546cc2cf0b45735831f54596c7f8841d3 100644
--- a/chrome/browser/devtools/devtools_window.cc
+++ b/chrome/browser/devtools/devtools_window.cc
@@ -840,7 +840,8 @@ WebContents* DevToolsWindow::OpenURLFromTab(
 void DevToolsWindow::ActivateContents(WebContents* contents) {
   if (is_docked_) {
     WebContents* inspected_tab = GetInspectedWebContents();
-    inspected_tab->GetDelegate()->ActivateContents(inspected_tab);
+    if (inspected_tab)
+      inspected_tab->GetDelegate()->ActivateContents(inspected_tab);
   } else if (browser_) {
     browser_->window()->Activate();
   }