Add throttling to corrupt policy extensions reinstall

chrome/browser/extensions/chrome_content_verifier_delegate.cc

Index: chrome/browser/extensions/chrome_content_verifier_delegate.cc
diff --git a/chrome/browser/extensions/chrome_content_verifier_delegate.cc b/chrome/browser/extensions/chrome_content_verifier_delegate.cc
index d6ea2c6af5de5f0ca117ef299d4580447feb2da4..9acc93869a0240ff19feccc86b1f1569eff4d14a 100644
--- a/chrome/browser/extensions/chrome_content_verifier_delegate.cc
+++ b/chrome/browser/extensions/chrome_content_verifier_delegate.cc
@@ -11,10 +11,12 @@
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
-#include "base/syslog_logging.h"
+#include "base/lazy_instance.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/string_util.h"
+#include "base/syslog_logging.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "base/version.h"
 #include "build/build_config.h"
 #include "chrome/browser/extensions/extension_service.h"
@@ -30,6 +32,7 @@
 #include "extensions/common/extensions_client.h"
 #include "extensions/common/manifest.h"
 #include "extensions/common/manifest_url_handlers.h"
+#include "net/base/backoff_entry.h"
 #include "net/base/escape.h"
 
 #if defined(OS_CHROMEOS)
@@ -41,6 +44,33 @@ namespace {
 const char kContentVerificationExperimentName[] =
     "ExtensionContentVerification";
 
+const net::BackoffEntry::Policy kPolicyReinstallBackoffPolicy = {
+    // num_errors_to_ignore
+    1,
+
+    // initial_delay_ms (note that we set 'always_use_initial_delay' to false
+    // below)
+    100,
+
+    // multiply_factor
+    2,
+
+    // jitter_factor
+    0.1,
+
+    // maximum_backoff_ms (30 minutes)
+    1000 * 60 * 30,
+
+    // entry_lifetime_ms (6 hours)
+    1000 * 60 * 60 * 6,
+
+    // always_use_initial_delay
+    false,
+};
+
+base::LazyInstance<base::Callback<void(base::TimeDelta delay)>>

[Devlin, 2016/11/29 22:31:24]

Any need for this to a be a lazy instance rather than just a raw ptr (and then
make sure it doesn't go out of scope in the test)?

[asargent_no_longer_on_chrome, 2016/11/30 00:11:48]

I think I did it this way out of habit because we normally pass Callback's by
value, but a raw pointer works too, so I've switched to that since it's a little
simpler. 

+    g_reinstall_action_for_test = LAZY_INSTANCE_INITIALIZER;
+
 }  // namespace
 
 namespace extensions {
@@ -186,7 +216,27 @@ void ChromeContentVerifierDelegate::VerifyFailed(
                       << extension->path().value();
       pending_manager->ExpectPolicyReinstallForCorruption(extension_id);
       service->DisableExtension(extension_id, Extension::DISABLE_CORRUPTED);
-      service->CheckForExternalUpdates();
+
+      net::BackoffEntry* backoff_entry = nullptr;
+      auto iter = policy_reinstall_backoff_.find(extension_id);
+      if (iter != policy_reinstall_backoff_.end()) {
+        backoff_entry = iter->second.get();
+      } else {
+        policy_reinstall_backoff_[extension_id] =
+            base::MakeUnique<net::BackoffEntry>(&kPolicyReinstallBackoffPolicy);
+        backoff_entry = policy_reinstall_backoff_[extension_id].get();

[Devlin, 2016/11/29 22:31:24]

nit: you could avoid a double look-up with either:
auto new_backoff_entry = base::MakeUnique<>(...);
backoff_entry = new_backoff_entry.get();
policy_reinstall_backoff_[extension_id] = std::move(new_backoff_entry)

or

backoff_entry =
    policy_reinstall_backoff_.insert(std::make_pair(
        extension_id, base::MakeUnique<>(...))).first->second;

[asargent_no_longer_on_chrome, 2016/11/30 00:11:48]

Done.

+      }
+      backoff_entry->InformOfRequest(false);
+
+      base::TimeDelta reinstall_delay = backoff_entry->GetTimeUntilRelease();
+      if (!g_reinstall_action_for_test.Get().is_null()) {
+        g_reinstall_action_for_test.Get().Run(reinstall_delay);
+      } else {
+        base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
+            FROM_HERE, base::Bind(&ExtensionService::CheckForExternalUpdates,
+                                  service->AsWeakPtr()),
+            reinstall_delay);
+      }
       return;
     }
     DLOG(WARNING) << "Disabling extension " << extension_id << " ('"
@@ -205,5 +255,10 @@ void ChromeContentVerifierDelegate::VerifyFailed(
   }
 }
 
+// static
+void ChromeContentVerifierDelegate::set_policy_reinstall_action_for_test(
+    base::Callback<void(base::TimeDelta delay)> action) {
+  g_reinstall_action_for_test.Get() = action;
+}
 
 }  // namespace extensions