Fix some WebContents leaks in prerendering tests

chrome/browser/android/offline_pages/prerender_adapter_unittest.cc

Index: chrome/browser/android/offline_pages/prerender_adapter_unittest.cc
diff --git a/chrome/browser/android/offline_pages/prerender_adapter_unittest.cc b/chrome/browser/android/offline_pages/prerender_adapter_unittest.cc
index 3c36eb060d6283c1cfcaadf35d78c1a021a18e8c..d17d256cd4f3ee14d4e42e408122e7db80e49215 100644
--- a/chrome/browser/android/offline_pages/prerender_adapter_unittest.cc
+++ b/chrome/browser/android/offline_pages/prerender_adapter_unittest.cc
@@ -201,8 +201,9 @@ TEST_F(PrerenderAdapterTest, StartPrerenderFailsForUnsupportedScheme) {
   if (base::SysInfo::IsLowEndDevice())
     return;
 
-  content::WebContents* session_contents = content::WebContents::Create(
-      content::WebContents::CreateParams(profile()));
+  std::unique_ptr<content::WebContents> session_contents(
+      content::WebContents::Create(
+          content::WebContents::CreateParams(profile())));
   content::SessionStorageNamespace* sessionStorageNamespace =
       session_contents->GetController().GetDefaultSessionStorageNamespace();
   gfx::Size renderWindowSize = session_contents->GetContainerBounds().size();
@@ -218,8 +219,9 @@ TEST_F(PrerenderAdapterTest, StartPrerenderSucceeds) {
   if (base::SysInfo::IsLowEndDevice())
     return;
 
-  content::WebContents* session_contents = content::WebContents::Create(
-      content::WebContents::CreateParams(profile()));
+  std::unique_ptr<content::WebContents> session_contents(
+      content::WebContents::Create(
+          content::WebContents::CreateParams(profile())));
   content::SessionStorageNamespace* sessionStorageNamespace =
       session_contents->GetController().GetDefaultSessionStorageNamespace();
   gfx::Size renderWindowSize = session_contents->GetContainerBounds().size();