content/common/debug_utils.h

// Copyright 2021 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.

#ifndef CONTENT_COMMON_DEBUG_UTILS_H_
#define CONTENT_COMMON_DEBUG_UTILS_H_

namespace content {

// There are cases that require debugging of complex multiprocess scenarios in
// which tools such as DumpWithoutCrashing and tracing can be useful.
// The goal of this enum is to be able to log to UMA when such complex scenarios
// occur with two goals:
// * Get an idea of the magnitute of the problem, since just crash reports
//   cannot express this, given they are throttled client side.
// * For clients which have continuous tracing enabled, upload a snapshot of the
//   trace to aid understanding of the interactions between all processes.
//
// Usage: Add a new value to the DebugScenario enum below and call
//   CaptureTraceForNavigationDebugScenario(YOUR_NEW_ENUM_VALUE);
// from the location where you are hitting the scenario you care about.
//
// NOTE: Do not renumber elements in this list. Add new entries at the end.
// Items may be renamed but do not change the values. We rely on the enum values
// in histograms.

enum class DebugScenario {
  kDebugSameDocNavigationDocIdMismatch = 1,

  // A non-main frame navigation with old_page_info set was detected.
  kDebugNonMainFrameWithOldPageInfo = 2,

  // Metrics and the bfcache situations do not match.
  kDebugBackForwardCacheMetricsMismatch = 3,

  // Detected a mismatch between the origin to commit as calculated on 1) the
  // browser-side VS 2) the renderer-side.
  kDebugBrowserVsRendererOriginToCommit = 4,

  // Evict-Restore race in Back Forward Cache - Renderer requested a frame be
  // evicted from cache, but the frame is no longer in the cache.
  kDebugBackForwardCacheEvictRestoreRace = 5,

  // HTTP response_head was unexpectedly nullptr even for HTTP or HTTPS schemes.
  kDebugNoResponseHeadForHttpOrHttps = 6,

  // RenderViewHost is not present when trying to create a new subframe's
  // RenderFrameProxyHost.
  kDebugSubframeProxyCreationWithNoRVH = 7,

  // BackForwardCacheEntry exists for a subframe history navigation.
  kDebugBackForwardCacheEntryExistsOnSubframeHistoryNav = 8,

  // RenderFrameProxyHost does not exist when trying to call
  // RenderFrameProxyHost::SetFocusedFrame().
  kDebugNoRenderFrameProxyHostOnSetFocusedFrame = 9,

  // After making changes, you MUST update the histograms xml by running:
  // "python tools/metrics/histograms/update_debug_scenarios.py"
  kMaxValue = kDebugNoRenderFrameProxyHostOnSetFocusedFrame,
};

// The tracing categories enabled for debugging navigation scenarios can be
// found in server-side studies config for slow reports.
void CaptureTraceForNavigationDebugScenario(DebugScenario scenario);

}  // namespace content

#endif  // CONTENT_COMMON_DEBUG_UTILS_H_