[BlobStorage] Possible test segfault mitigation

content/browser/blob_storage/blob_storage_browsertest.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/run_loop.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "content/browser/blob_storage/chrome_blob_storage_context.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/web_contents.h"
@@ skipping 31 matching lines @@
   }
 
   void SetBlobLimits() {
     GetMemoryController()->set_limits_for_testing(limits_);
   }
 
   storage::BlobMemoryController* GetMemoryController() {
     content::ChromeBlobStorageContext* blob_context =
         ChromeBlobStorageContext::GetFor(
             shell()->web_contents()->GetBrowserContext());
+    if (!blob_context->context())
+      return nullptr;
     return blob_context->context()->mutable_memory_controller();
   }
 
   void SimpleTest(const GURL& test_url, bool incognito = false) {
     // The test page will perform tests on blob storage, then navigate to either
     // a #pass or #fail ref.
     Shell* the_browser = incognito ? CreateOffTheRecordBrowser() : shell();
+    ASSERT_TRUE(the_browser);
 
     VLOG(0) << "Navigating to URL and blocking. " << test_url.spec();
     NavigateToURLBlockUntilNavigationsComplete(the_browser, test_url, 2);
     VLOG(0) << "Navigation done.";
     std::string result =
         the_browser->web_contents()->GetLastCommittedURL().ref();
     if (result != "pass") {
       std::string js_result;
       ASSERT_TRUE(ExecuteScriptAndExtractString(
           the_browser, "window.domAutomationController.send(getLog())",
           &js_result));
       FAIL() << "Failed: " << js_result;
     }
   }
 
  protected:
   storage::BlobStorageLimits limits_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(BlobStorageBrowserTest);
 };
 
 IN_PROC_BROWSER_TEST_F(BlobStorageBrowserTest, BlobCombinations) {
   SetBlobLimits();
   SimpleTest(GetTestUrl("blob_storage", "blob_creation_and_slicing.html"));
   storage::BlobMemoryController* memory_controller = GetMemoryController();
+  ASSERT_TRUE(memory_controller);
   // Our exact usages depend on IPC message ordering & garbage collection.
   // Since this is basically random, we just check bounds.
   EXPECT_LT(0u, memory_controller->memory_usage());
   EXPECT_LT(0ul, memory_controller->disk_usage());
   EXPECT_GT(memory_controller->disk_usage(),
             static_cast<uint64_t>(memory_controller->memory_usage()));
   EXPECT_GT(limits_.max_blob_in_memory_space,
             memory_controller->memory_usage());
   EXPECT_GT(limits_.effective_max_disk_space, memory_controller->disk_usage());
   shell()->Close();
 
   // Make sure we run all file / io tasks.
   base::RunLoop().RunUntilIdle();
   BrowserThread::GetBlockingPool()->FlushForTesting();
   base::RunLoop().RunUntilIdle();
 }
 
 }  // namespace content