browser_tests failing on 2 builders

Builders failed on: 
- Linux ChromiumOS MSan Tests: 
  https://build.chromium.org/p/chromium.memory/builders/Linux%20ChromiumOS%20MSan%20Tests
- Linux MSan Tests: 
  https://build.chromium.org/p/chromium.memory/builders/Linux%20MSan%20Tests


Here's some of the output:

 RUN      ] SafeBrowsingRedirectTracking/WebstoreInlineInstallerRedirectTest.IncludesRedirectData/0
Xlib:  extension "RANDR" missing on display ":99".
[21341:21341:0501/135237.283968:WARNING:audio_manager.cc(293)] Multiple instances of AudioManager detected
[21341:21341:0501/135237.284074:WARNING:audio_manager.cc(254)] Multiple instances of AudioManager detected
[21341:21341:0501/135237.604241:WARNING:password_store_factory.cc(249)] Using basic (unencrypted) store for password storage. See https://chromium.googlesource.com/chromium/src/+/master/docs/linux_password_storage.md for more information about password storage options.
[21341:21341:0501/135238.497583:INFO:CONSOLE(8)] "Page loaded", source: http://app.com:55662/extensions/api_test/webstore_inline_install/install.html (8)
[21341:21392:0501/135238.530103:WARNING:embedded_test_server.cc(219)] Request not handled. Returning 404: /favicon.ico
[21341:21341:0501/135238.543479:INFO:CONSOLE(11)] "In runTest", source: http://app.com:55662/extensions/api_test/webstore_inline_install/install.html (11)
==21341==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x1537e69e in extensions::WebstoreInlineInstaller::GetJsonPostData() chrome/browser/extensions/webstore_inline_installer.cc:134:7
    #1 0x15397c0b in extensions::WebstoreStandaloneInstaller::BeginInstall() chrome/browser/extensions/webstore_standalone_installer.cc:73:32
    #2 0x15345ea3 in extensions::TabHelper::OnInlineWebstoreInstall(content::RenderFrameHost*, int, int, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, int) chrome/browser/extensions/tab_helper.cc:478:16
    #3 0x15343cf6 in DispatchToMethodImpl<extensions::TabHelper, void (extensions::TabHelper::*)(content::RenderFrameHost *, int, int, const std::__1::basic_string<char> &, int), content::RenderFrameHost, std::__1::tuple<int, int, std::__1::basic_string<char>, int>, 0, 1, 2, 3> ipc/ipc_message_templates.h:40:3
    #4 0x15343cf6 in DispatchToMethod<extensions::TabHelper, content::RenderFrameHost, int, int, const std::__1::basic_string<char> &, int, int, int, std::__1::basic_string<char>, int> ipc/ipc_message_templates.h:51:0
    #5 0x15343cf6 in bool IPC::MessageT<ExtensionHostMsg_InlineWebstoreInstall_Meta, std::__1::tuple<int, int, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, int>, void>::Dispatch<extensions::TabHelper, extensions::TabHelper, content::RenderFrameHost, void (extensions::TabHelper::*)(content::RenderFrameHost*, int, int, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, int)>(IPC::Message const*, extensions::TabHelper*, extensions::TabHelper*, content::RenderFrameHost*, void (extensions::TabHelper::*)(content::RenderFrameHost*, int, int, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, int)) ipc/ipc_message_templates.h:121:0
    #6 0x153431c0 in extensions::TabHelper::OnMessageReceived(IPC::Message const&, content::RenderFrameHost*) chrome/browser/extensions/tab_helper.cc:349:5
    #7 0x6b8af91 in content::WebContentsImpl::OnMessageReceived(content::RenderFrameHostImpl*, IPC::Message const&) content/browser/web_contents/web_contents_impl.cc:789:18
    #8 0x5f14616 in content::RenderFrameHostImpl::OnMessageReceived(IPC::Message const&) content/browser/frame_host/render_frame_host_impl.cc:729:18
    #9 0x66d478c in content::RenderProcessHostImpl::OnMessageReceived(IPC::Message const&) content/browser/renderer_host/render_process_host_impl.cc:2128:20
    #10 0x10b4fa0b in IPC::ChannelProxy::Context::OnDispatchMessage(IPC::Message const&) ipc/ipc_channel_proxy.cc:329:14
    #11 0xb761f75 in Run base/callback.h:91:12
    #12 0xb761f75 in base::debug::TaskAnnotator::RunTask(char const*, base::PendingTask*) base/debug/task_annotator.cc:59:0
    #13 0xb4eb213 in base::MessageLoop::RunTask(base::PendingTask*) base/message_loop/message_loop.cc:423:19
    #14 0xb4ecbe1 in base::MessageLoop::DeferOrRunPendingTask(base::PendingTask) base/message_loop/message_loop.cc:434:5
    #15 0xb4ee78e in base::MessageLoop::DoWork() base/message_loop/message_loop.cc:527:13
    #16 0xb4fe039 in HandleDispatch base/message_loop/message_pump_glib.cc:267:25
    #17 0xb4fe039 in base::(anonymous namespace)::WorkSourceDispatch(_GSource*, int (*)(void*), void*) base/message_loop/message_pump_glib.cc:109:0
    #18 0x7f065e6a53ce in g_main_dispatch /home/tom/chromium/src/third_party/instrumented_libraries/scripts/out/Instrumented-msan-chained-origins-trusty/gen/third_party/instrumented_libraries/libglib2.0-0/glib2.0-2.40.2/glib/gmain.c:3064:27
    #19 0x7f065e6a53ce in g_main_context_dispatch /home/tom/chromium/src/third_party/instrumented_libraries/scripts/out/Instrumented-msan-chained-origins-trusty/gen/third_party/instrumented_libraries/libglib2.0-0/glib2.0-2.40.2/glib/gmain.c:3663:0
    #20 0x7f065e6a6686 in g_main_context_iterate /home/tom/chromium/src/third_party/instrumented_libraries/scripts/out/Instrumented-msan-chained-origins-trusty/gen/third_party/instrumented_libraries/libglib2.0-0/glib2.0-2.40.2/glib/gmain.c:3734:5
    #21 0x7f065e6a6a1d in g_main_context_iteration /home/tom/chromium/src/third_party/instrumented_libraries/scripts/out/Instrumented-msan-chained-origins-trusty/gen/third_party/instrumented_libraries/libglib2.0-0/glib2.0-2.40.2/glib/gmain.c:3795:12
    #22 0xb4fd5d3 in base::MessagePumpGlib::Run(base::MessagePump::Delegate*) base/message_loop/message_pump_glib.cc:309:30
    #23 0xb4ea296 in base::MessageLoop::RunHandler() base/message_loop/message_loop.cc:387:10
    #24 0xb5a6ebc in base::RunLoop::Run() base/run_loop.cc:37:10
    #25 0x1c5cb81 in extensions::WebstoreInlineInstallerRedirectTest_IncludesRedirectData_Test::RunTestOnMainThread() chrome/browser/extensions/webstore_inline_installer_browsertest.cc:452:21
    #26 0xd3cb871 in content::BrowserTestBase::ProxyRunTestOnMainThreadLoop() content/public/test/browser_test_base.cc:309:5
    #27 0xca06dd6 in Run base/callback.h:80:12
    #28 0xca06dd6 in ChromeBrowserMainParts::PreMainMessageLoopRunImpl() chrome/browser/chrome_browser_main.cc:1916:0
    #29 0xca02514 in ChromeBrowserMainParts::PreMainMessageLoopRun() chrome/browser/chrome_browser_main.cc:1257:18
    #30 0x5a09926 in content::BrowserMainLoop::PreMainMessageLoopRun() content/browser/browser_main_loop.cc:1162:13
    #31 0x6adc1aa in Run base/callback.h:80:12
    #32 0x6adc1aa in content::StartupTaskRunner::RunAllTasksNow() content/browser/startup_task_runner.cc:45:0
    #33 0x5a01324 in content::BrowserMainLoop::CreateStartupTasks() content/browser/browser_main_loop.cc:957:25
    #34 0x5a17f90 in content::BrowserMainRunnerImpl::Initialize(content::MainFunctionParams const&) content/browser/browser_main_runner.cc:125:17
    #35 0x59f46ef in content::BrowserMain(content::MainFunctionParams const&) content/browser/browser_main.cc:42:32
    #36 0xb3ca74c in content::RunNamedProcessTypeMain(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, content::MainFunctionParams const&, content::ContentMainDelegate*) content/app/content_main_runner.cc:411:14
    #37 0xb3cd4bb in content::ContentMainRunnerImpl::Run() content/app/content_main_runner.cc:703:12
    #38 0x12e3a32e in service_manager::Main(service_manager::MainParams const&) services/service_manager/embedder/main.cc:450:29
    #39 0xb3c6fde in content::ContentMain(content::ContentMainParams const&) content/app/content_main.cc:19:10
    #40 0xd3ca8cf in content::BrowserTestBase::SetUp() content/public/test/browser_test_base.cc:265:3
    #41 0xb81bd64 in InProcessBrowserTest::SetUp() chrome/test/base/in_process_browser_test.cc:266:20
    #42 0xf74f1b7 in HandleExceptionsInMethodIfSupported<testing::Test, void> testing/gtest/src/gtest.cc:2458:12
    #43 0xf74f1b7 in testing::Test::Run() testing/gtest/src/gtest.cc:2470:0
    #44 0xf7521db in testing::TestInfo::Run() testing/gtest/src/gtest.cc:2656:11
    #45 0xf753779 in testing::TestCase::Run() testing/gtest/src/gtest.cc:2774:28
    #46 0xf77323d in testing::internal::UnitTestImpl::RunAllTests() testing/gtest/src/gtest.cc:4647:43
    #47 0xf7720ce in HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool> testing/gtest/src/gtest.cc:2458:12
    #48 0xf7720ce in testing::UnitTest::Run() testing/gtest/src/gtest.cc:4255:0
    #49 0xb869a90 in RUN_ALL_TESTS testing/gtest/include/gtest/gtest.h:2237:46
    #50 0xb869a90 in base::TestSuite::Run() base/test/test_suite.cc:271:0
    #51 0xb41d57b in ChromeTestSuiteRunner::RunTestSuite(int, char**) chrome/test/base/chrome_test_launcher.cc:62:38
    #52 0xd504e32 in content::LaunchTests(content::TestLauncherDelegate*, int, int, char**) content/public/test/test_launcher.cc:520:31
    #53 0xb41d36c in main chrome/test/base/browser_tests_main.cc:15:10
    #54 0x7f065585cf44 in __libc_start_main /build/eglibc-MjiXCM/eglibc-2.19/csu/libc-start.c:287:0
    #55 0x715f65 in _start ??:0:0

  Uninitialized value was created by a heap allocation
    #0 0x785239 in operator new(unsigned long) ??:0:0
    #1 0x1c6a80d in extensions::WebstoreInlineInstallerForTestFactory::CreateInstaller(content::WebContents*, content::RenderFrameHost*, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, GURL const&, base::Callback<void (bool, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, extensions::webstore_install::Result), (base::internal::CopyMode)1, (base::internal::RepeatMode)1> const&) chrome/browser/extensions/webstore_inline_installer_browsertest.cc:200:23
    #2 0x15345e35 in extensions::TabHelper::OnInlineWebstoreInstall(content::RenderFrameHost*, int, int, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, int) chrome/browser/extensions/tab_helper.cc:476:45
    #3 0x15343cf6 in DispatchToMethodImpl<extensions::TabHelper, void (extensions::TabHelper::*)(content::RenderFrameHost *, int, int, const std::__1::basic_string<char> &, int), content::RenderFrameHost, std::__1::tuple<int, int, std::__1::basic_string<char>, int>, 0, 1, 2, 3> ipc/ipc_message_templates.h:40:3
    #4 0x15343cf6 in DispatchToMethod<extensions::TabHelper, content::RenderFrameHost, int, int, const std::__1::basic_string<char> &, int, int, int, std::__1::basic_string<char>, int> ipc/ipc_message_templates.h:51:0
    #5 0x15343cf6 in bool IPC::MessageT<ExtensionHostMsg_InlineWebstoreInstall_Meta, std::__1::tuple<int, int, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, int>, void>::Dispatch<extensions::TabHelper, extensions::TabHelper, content::RenderFrameHost, void (extensions::TabHelper::*)(content::RenderFrameHost*, int, int, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, int)>(IPC::Message const*, extensions::TabHelper*, extensions::TabHelper*, content::RenderFrameHost*, void (extensions::TabHelper::*)(content::RenderFrameHost*, int, int, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, int)) ipc/ipc_message_templates.h:121:0
    #6 0x153431c0 in extensions::TabHelper::OnMessageReceived(IPC::Message const&, content::RenderFrameHost*) chrome/browser/extensions/tab_helper.cc:349:5
    #7 0x6b8af91 in content::WebContentsImpl::OnMessageReceived(content::RenderFrameHostImpl*, IPC::Message const&) content/browser/web_contents/web_contents_impl.cc:789:18
    #8 0x5f14616 in content::RenderFrameHostImpl::OnMessageReceived(IPC::Message const&) content/browser/frame_host/render_frame_host_impl.cc:729:18
    #9 0x66d478c in content::RenderProcessHostImpl::OnMessageReceived(IPC::Message const&) content/browser/renderer_host/render_process_host_impl.cc:2128:20
    #10 0x10b4fa0b in IPC::ChannelProxy::Context::OnDispatchMessage(IPC::Message const&) ipc/ipc_channel_proxy.cc:329:14
    #11 0xb761f75 in Run base/callback.h:91:12
    #12 0xb761f75 in base::debug::TaskAnnotator::RunTask(char const*, base::PendingTask*) base/debug/task_annotator.cc:59:0
    #13 0xb4eb213 in base::MessageLoop::RunTask(base::PendingTask*) base/message_loop/message_loop.cc:423:19
    #14 0xb4ecbe1 in base::MessageLoop::DeferOrRunPendingTask(base::PendingTask) base/message_loop/message_loop.cc:434:5
    #15 0xb4ee78e in base::MessageLoop::DoWork() base/message_loop/message_loop.cc:527:13
    #16 0xb4fe039 in HandleDispatch base/message_loop/message_pump_glib.cc:267:25
    #17 0xb4fe039 in base::(anonymous namespace)::WorkSourceDispatch(_GSource*, int (*)(void*), void*) base/message_loop/message_pump_glib.cc:109:0
    #18 0x7f065e6a53ce in g_main_dispatch /home/tom/chromium/src/third_party/instrumented_libraries/scripts/out/Instrumented-msan-chained-origins-trusty/gen/third_party/instrumented_libraries/libglib2.0-0/glib2.0-2.40.2/glib/gmain.c:3064:27
    #19 0x7f065e6a53ce in g_main_context_dispatch /home/tom/chromium/src/third_party/instrumented_libraries/scripts/out/Instrumented-msan-chained-origins-trusty/gen/third_party/instrumented_libraries/libglib2.0-0/glib2.0-2.40.2/glib/gmain.c:3663:0
    #20 0x7f065e6a6686 in g_main_context_iterate /home/tom/chromium/src/third_party/instrumented_libraries/scripts/out/Instrumented-msan-chained-origins-trusty/gen/third_party/instrumented_libraries/libglib2.0-0/glib2.0-2.40.2/glib/gmain.c:3734:5
    #21 0x7f065e6a6a1d in g_main_context_iteration /home/tom/chromium/src/third_party/instrumented_libraries/scripts/out/Instrumented-msan-chained-origins-trusty/gen/third_party/instrumented_libraries/libglib2.0-0/glib2.0-2.40.2/glib/gmain.c:3795:12
    #22 0xb4fd5d3 in base::MessagePumpGlib::Run(base::MessagePump::Delegate*) base/message_loop/message_pump_glib.cc:309:30
    #23 0xb4ea296 in base::MessageLoop::RunHandler() base/message_loop/message_loop.cc:387:10
    #24 0xb5a6ebc in base::RunLoop::Run() base/run_loop.cc:37:10

find-it identified https://codereview.chromium.org/2779643002/ . Which looks right. I'm going to revert it.