Revert "PPAPI: Add NetworkIsolationKeys to proxy lookup requests."

This reverts commit 45fb6502.

Reason for revert: Test failure: crbug.com/1051400

Original change's description:
> PPAPI:  Add NetworkIsolationKeys to proxy lookup requests.
> 
> This is needed to correctly isolate any DNS requests made by PPAPI in
> the context of one page from those made in the context of other pages.
> 
> This is a reland of
> https://chromium-review.googlesource.com/c/chromium/src/+/2008050. The
> original CL was reverted because the DNS layer auto-detects whether the
> current network supports IPv6, and the detection value was changing in
> the middle of tests. When the value changes, the cache key used for the
> DNS layer changes, which was resulting in cache misses.
> 
> To fix the issue, the test now relies on IPv4 DNS lookups, which don't
> have this issue.
> 
> Bug: 1021661
> Change-Id: I959b81d0a3fc5973cde4ba7a0ccfd0c501ffc235
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2050743
> Commit-Queue: Matt Menke <mmenke@chromium.org>
> Reviewed-by: Raymes Khoury <raymes@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#740487}

TBR=raymes@chromium.org,mmenke@chromium.org

Change-Id: I40432831baa19cdf040c38684fb785f48816873f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1021661
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2051644Reviewed-by: Hajime Hoshi <hajimehoshi@chromium.org>
Commit-Queue: Hajime Hoshi <hajimehoshi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#740580}

chrome/test/ppapi/ppapi_browsertest.cc

@@ -1269,17 +1269,7 @@ TEST_PPAPI_NACL_DISALLOWED_SOCKETS(UDPSocketPrivateDisallowed)
 // is present in the DNS cache with the NetworkIsolationKey associated with the
 // foreground WebContents - this is needed so as not to leak what hostnames were
 // looked up across tabs with different first party origins.
-//
-// The lookup checks for an IPv4-only cache entry, as UNSPECIFIED lookups are
-// sometimes replaced with IPv4-only lookups, based on the result of that probe
-// of whether the local network has IPv6 connectivity. For unknown reasons, the
-// results of this probe can change in the middle of a test on the bots, which
-// changes the used cache key. To avoid that issue, just use A lookups.
-//
-// See https://crbug.com/1042354 for some discussion of the issue.
-void CheckTestHostNameUsedWithCorrectNetworkIsolationKey(
-    Browser* browser,
-    bool include_canonical_name) {
+void CheckTestHostNameUsedWithCorrectNetworkIsolationKey(Browser* browser) {
   network::mojom::NetworkContext* network_context =
       content::BrowserContext::GetDefaultStoragePartition(browser->profile())
           ->GetNetworkContext();
@@ -1290,10 +1280,8 @@ void CheckTestHostNameUsedWithCorrectNetworkIsolationKey(
       network::mojom::ResolveHostParameters::New();
   // Cache only lookup.
   params->source = net::HostResolverSource::LOCAL_ONLY;
-  // A-only lookup.
-  params->dns_query_type = net::DnsQueryType::A;
   // Match the parameters used by the test.
-  params->include_canonical_name = include_canonical_name;
+  params->include_canonical_name = true;
   net::NetworkIsolationKey network_isolation_key =
       browser->tab_strip_model()
           ->GetActiveWebContents()
@@ -1325,8 +1313,7 @@ void CheckTestHostNameUsedWithCorrectNetworkIsolationKey(
 #define RUN_HOST_RESOLVER_SUBTESTS                                             \
   RunTestViaHTTP(LIST_TEST(HostResolver_Empty) LIST_TEST(HostResolver_Resolve) \
                      LIST_TEST(HostResolver_ResolveIPv4));                     \
-  CheckTestHostNameUsedWithCorrectNetworkIsolationKey(                         \
-      browser(), true /* include_canonical_name */)
+  CheckTestHostNameUsedWithCorrectNetworkIsolationKey(browser())
 
 IN_PROC_BROWSER_TEST_F(OutOfProcessPPAPITest, HostResolverCrash_Basic) {
   if (content::IsInProcessNetworkService())
@@ -2195,33 +2182,7 @@ TEST_PPAPI_NACL(MAYBE_MediaStreamVideoTrack)
 
 TEST_PPAPI_NACL(MouseCursor)
 
-// Proxy configuration test. The PPAPI code used by these tests is in
-// ppapi/tests/test_network_proxy.cc.
-
-IN_PROC_BROWSER_TEST_F(OutOfProcessPPAPITest, NetworkProxy) {
-  RunTestViaHTTP(STRIP_PREFIXES(NetworkProxy));
-  CheckTestHostNameUsedWithCorrectNetworkIsolationKey(
-      browser(), false /* include_canonical_name */);
-}
-
-IN_PROC_BROWSER_TEST_F(PPAPINaClNewlibTest, NetworkProxy) {
-  RunTestViaHTTP(STRIP_PREFIXES(NetworkProxy));
-  CheckTestHostNameUsedWithCorrectNetworkIsolationKey(
-      browser(), false /* include_canonical_name */);
-}
-
-IN_PROC_BROWSER_TEST_F(PPAPINaClPNaClTest, MAYBE_PPAPI_NACL(NetworkProxy)) {
-  RunTestViaHTTP(STRIP_PREFIXES(NetworkProxy));
-  CheckTestHostNameUsedWithCorrectNetworkIsolationKey(
-      browser(), false /* include_canonical_name */);
-}
-
-IN_PROC_BROWSER_TEST_F(PPAPINaClPNaClNonSfiTest,
-                       MAYBE_PNACL_NONSFI(NetworkProxy)) {
-  RunTestViaHTTP(STRIP_PREFIXES(NetworkProxy));
-  CheckTestHostNameUsedWithCorrectNetworkIsolationKey(
-      browser(), false /* include_canonical_name */);
-}
+TEST_PPAPI_NACL(NetworkProxy)
 
 // TODO(crbug.com/619765): get working on CrOS build.
 #if defined(OS_CHROMEOS)

chrome/test/ppapi/ppapi_test.cc

@@ -160,24 +160,9 @@ void PPAPITestBase::SetUpCommandLine(base::CommandLine* command_line) {
 
   // Smooth scrolling confuses the scrollbar test.
   command_line->AppendSwitch(switches::kDisableSmoothScrolling);
-
-  // For a particular host name, resolve another specific host name (which
-  // should then be added to the DNS cache), and then return a particular proxy.
-  // Otherwise, return DIRECT.
-  command_line->AppendSwitchASCII(switches::kProxyPacUrl,
-                                  "data:,"
-                                  "function FindProxyForURL(url, host) {"
-                                  "  if (host == 'use.proxy.test') {"
-                                  "    dnsResolve('host_resolver.test');"
-                                  "    return 'PROXY proxy.test';"
-                                  "  }"
-                                  "  return 'DIRECT'"
-                                  "}");
 }
 
 void PPAPITestBase::SetUpOnMainThread() {
-  host_resolver()->AddRule("host_resolver.test",
-                           embedded_test_server()->host_port_pair().host());
   host_resolver()->AddRuleWithFlags(
       "host_resolver.test", embedded_test_server()->host_port_pair().host(),
       net::HOST_RESOLVER_CANONNAME);

content/browser/renderer_host/pepper/pepper_network_proxy_host.cc

@@ -46,9 +46,9 @@ bool LookUpProxyForURLCallback(
   StoragePartition* storage_partition = BrowserContext::GetStoragePartition(
       site_instance->GetBrowserContext(), site_instance);
 
+  // TODO(https://crbug.com/1021661): Pass in a non-empty NetworkIsolationKey.
   storage_partition->GetNetworkContext()->LookUpProxyForURL(
-      url, render_frame_host->GetNetworkIsolationKey(),
-      std::move(proxy_lookup_client));
+      url, net::NetworkIsolationKey::Todo(), std::move(proxy_lookup_client));
   return true;
 }
 

content/test/ppapi/ppapi_browsertest.cc

@@ -122,6 +122,8 @@ TEST_PPAPI_OUT_OF_PROCESS(MessageHandler)
 TEST_PPAPI_OUT_OF_PROCESS(MessageLoop_Basics)
 TEST_PPAPI_OUT_OF_PROCESS(MessageLoop_Post)
 
+TEST_PPAPI_OUT_OF_PROCESS(NetworkProxy)
+
 // TODO(danakj): http://crbug.com/115286
 TEST_PPAPI_IN_PROCESS(DISABLED_Scrollbar)
 // http://crbug.com/89961

ppapi/tests/test_network_proxy.cc

@@ -33,12 +33,15 @@ std::string TestNetworkProxy::TestGetProxyForURL() {
   // Assume no one configures a proxy for localhost.
   ASSERT_EQ("DIRECT", callback.output().AsString());
 
-  callback.WaitForResult(pp::NetworkProxy::GetProxyForURL(
-      instance_, pp::Var("https://use.proxy.test/"), callback.GetCallback()));
+  callback.WaitForResult(
+      pp::NetworkProxy::GetProxyForURL(instance_,
+                                       pp::Var("http://www.google.com"),
+                                       callback.GetCallback()));
   CHECK_CALLBACK_BEHAVIOR(callback);
   ASSERT_EQ(PP_OK, callback.result());
   output = callback.output();
-  ASSERT_EQ("PROXY proxy.test:80", callback.output().AsString());
+  // Don't know what the proxy might be, but it should be a valid result.
+  ASSERT_TRUE(output.is_string());
 
   callback.WaitForResult(
       pp::NetworkProxy::GetProxyForURL(instance_,