net: Remove typedef net::URLRequest URLRequest;

tools/heapcheck/suppressions.txt

 # There are three kinds of suppressions in this file.
 # 1. third party stuff we have no control over
 #
 # 2. intentional unit test errors, or stuff that is somehow a false positive
 # in our own code, or stuff that is so trivial it's not worth fixing
 #
 # 3. Suppressions for real chromium bugs that are not yet fixed.
 # These should all be in chromium's bug tracking system (but a few aren't yet).
 # Periodically we should sweep this file and the bug tracker clean by
 # running overnight and removing outdated bugs/suppressions.
@@ skipping 135 matching lines @@
   fun:std::vector::push_back
   fun:IPC::ChannelProxy::Context::OnAddFilter
   fun:*DispatchToMethod
   fun:RunnableMethod::Run
 }
 {
    bug_34570
    Heapcheck:Leak
    fun:URLRequestHttpJob::Factory
    fun:URLRequestJobManager::CreateJob
-   fun:URLRequest::Start
+   fun:net::URLRequest::Start
    fun:URLRequestTest_CancelTest_DuringCookiePolicy_Test::TestBody
    fun:testing::HandleExceptionsInMethodIfSupported
    fun:testing::Test::Run
    fun:testing::TestInfo::Run
    fun:testing::TestCase::Run
    fun:testing::internal::UnitTestImpl::RunAllTests
    fun:testing::HandleExceptionsInMethodIfSupported
    fun:testing::UnitTest::Run
    fun:TestSuite::Run
    fun:main
@@ skipping 880 matching lines @@
    bug_60872
    Heapcheck:Leak
    fun:base::BaseTimer::Start
    fun:ReloadButtonGtk::OnClicked
    fun:ReloadButtonGtk::OnClickedThunk
    fun:g_closure_invoke
    fun:ReloadButtonGtkTest_*_Test::TestBody
    fun:testing::HandleExceptionsInMethodIfSupported
    fun:testing::Test::Run
 }