WebUI Tab Strip: Update DCHECK to CHECK to investigate crash

Bug: 1141573
Change-Id: I2ac4c7156e7b7e997bcadb0e187a53d8adfd3a4f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2496024Reviewed-by: Collin Baker <collinbaker@chromium.org>
Commit-Queue: John Lee <johntlee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#820508}

chrome/browser/ui/webui/tab_strip/tab_strip_ui_handler.cc

@@ -760,8 +760,8 @@ void TabStripUIHandler::HandleShowTabContextMenu(const base::ListValue* args) {
   const bool got_tab = extensions::ExtensionTabUtil::GetTabById(
       tab_id, browser_->profile(), true /* include_incognito */, &browser,
       nullptr, nullptr, &tab_index);
-  DCHECK(got_tab);
-  DCHECK_EQ(browser, browser_);
+  CHECK(got_tab);
+  CHECK_EQ(browser, browser_);
 
   DCHECK(embedder_);
   embedder_->ShowContextMenuAtPoint(