A simple minidump writer for postmortem stability reports.

Enables writing a minimal minidump for wrapping a StabilityReport protocol buffer. The minidump is meant to be valid for registration with the Crashpad reporter (includes the Crashpad info stream).

BUG=620813

Review-Url: https://codereview.chromium.org/2327043002
Cr-Commit-Position: refs/heads/master@{#418863}

components/browser_watcher/BUILD.gn

@@ -2,6 +2,14 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//third_party/protobuf/proto_library.gni")
+
+proto_library("stability_report_proto") {
+  sources = [
+    "stability_report.proto",
+  ]
+}
+
 static_library("browser_watcher") {
   # This is a separate lib to minimize the dependencies for its
   # hosting binary "chrome_watcher.dll".
@@ -33,12 +41,28 @@ static_library("browser_watcher_client") {
   ]
 }
 
+static_library("postmortem_minidump_writer") {
+  # TODO(manzagop): remove this lib once Crashpad writes the minidumps.
+  sources = [
+    "postmortem_minidump_writer.h",
+    "postmortem_minidump_writer_win.cc",
+  ]
+  deps = [
+    ":stability_report_proto",
+    "//base",
+    "//third_party/crashpad/crashpad/client",
+    "//third_party/crashpad/crashpad/minidump",
+    "//third_party/crashpad/crashpad/util",
+  ]
+}
+
 source_set("unit_tests") {
   testonly = true
   sources = [
     "endsession_watcher_window_win_unittest.cc",
     "exit_code_watcher_win_unittest.cc",
     "exit_funnel_win_unittest.cc",
+    "postmortem_minidump_writer_win_unittest.cc",
     "watcher_client_win_unittest.cc",
     "watcher_metrics_provider_win_unittest.cc",
     "window_hang_monitor_win_unittest.cc",
@@ -47,8 +71,17 @@ source_set("unit_tests") {
   deps = [
     ":browser_watcher",
     ":browser_watcher_client",
+    ":postmortem_minidump_writer",
+    ":stability_report_proto",
     "//base",
     "//base/test:test_support",
     "//testing/gtest",
+    "//third_party/crashpad/crashpad/client",
+
+    # TODO(manzagop): remove this lib once Crashpad writes the minidumps.
+    "//third_party/crashpad/crashpad/compat",
+    "//third_party/crashpad/crashpad/minidump",
+    "//third_party/crashpad/crashpad/snapshot",
+    "//third_party/crashpad/crashpad/util",
   ]
 }

components/browser_watcher/DEPS

 include_rules = [
-  "+components/metrics"
+  "+components/metrics",
+  "+third_party/crashpad/crashpad",
 ]

components/browser_watcher/postmortem_minidump_writer.h

+// Copyright 2016 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 COMPONENTS_BROWSER_WATCHER_POSTMORTEM_MINIDUMP_WRITER_H_
+#define COMPONENTS_BROWSER_WATCHER_POSTMORTEM_MINIDUMP_WRITER_H_
+
+#include <stdint.h>
+
+#include <string>
+
+#include "base/files/file.h"
+#include "components/browser_watcher/stability_report.pb.h"
+#include "third_party/crashpad/crashpad/util/misc/uuid.h"
+
+namespace browser_watcher {
+
+// Minidump information required by the Crashpad reporter.
+struct MinidumpInfo {
+  crashpad::UUID client_id;    // The client's identifier.
+  crashpad::UUID report_id;    // The report's identifier.
+  std::string product_name;    // The product name to be used by the reporter.
+  std::string version_number;  // The product's version number.
+};
+
+// Write to |minidump_file| a minimal minidump that wraps |report|. Returns
+// true on success, false otherwise.
+// Note: the caller owns |minidump_file| and is responsible for keeping it valid
+// for this function's duration. |minidump_file| is expected to be empty
+// and a binary stream.
+bool WritePostmortemDump(base::PlatformFile minidump_file,
+                         const StabilityReport& report,
+                         const MinidumpInfo& minidump_info);
+
+}  // namespace browser_watcher
+
+#endif  // COMPONENTS_BROWSER_WATCHER_POSTMORTEM_MINIDUMP_WRITER_H_

components/browser_watcher/postmortem_minidump_writer_win.cc

+// Copyright 2016 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.
+//
+// Note: aside from using windows headers to obtain the definitions of minidump
+//     structures, nothing here is windows specific. This seems like the best
+//     approach given this code is for temporary experimentation on Windows.
+//     Longer term, Crashpad will take over the minidump writing in this case as
+//     well.
+
+#include "components/browser_watcher/postmortem_minidump_writer.h"
+
+#include <windows.h>  // NOLINT
+#include <dbghelp.h>
+
+#include <map>
+#include <type_traits>
+#include <vector>
+
+#include "base/files/file_util.h"
+#include "base/macros.h"
+#include "base/numerics/safe_math.h"
+#include "base/strings/string_piece.h"
+#include "third_party/crashpad/crashpad/minidump/minidump_extensions.h"
+
+namespace browser_watcher {
+
+namespace {
+
+// The stream type assigned to the minidump stream that holds the serialized
+// stability report.
+// Note: the value was obtained by adding 1 to the stream type used for holding
+// the SyzyAsan proto.
+// TODO(manzagop): centralize the stream type definitions to avoid issues.
+const uint32_t kStabilityReportStreamType = 0x4B6B0002;
+
+int64_t GetFileOffset(base::File* file) {
+  DCHECK(file);
+  return file->Seek(base::File::FROM_CURRENT, 0LL);
+}
+
+// Returns true if the file is empty, and false if the file is not empty or if
+// there is an error.
+bool IsFileEmpty(base::File* file) {
+  DCHECK(file);
+  int64_t end = file->Seek(base::File::FROM_END, 0LL);
+  return end == 0LL;
+}
+
+// A class with functionality for writing minimal minidump containers to wrap
+// postmortem stability reports.
+// TODO(manzagop): remove this class once Crashpad takes over writing postmortem
+//     minidumps.
+// TODO(manzagop): revisit where the module information should be transported,
+//     in the protocol buffer or in a module stream.
+class PostmortemMinidumpWriter {
+ public:
+  PostmortemMinidumpWriter();
+  ~PostmortemMinidumpWriter();
+
+  // Write to |minidump_file| a minimal minidump that wraps |report|. Returns
+  // true on success, false otherwise.
+  // Note: the caller owns |minidump_file| and is responsible for keeping it
+  // valid for this object's lifetime. |minidump_file| is expected to be empty
+  // and a binary stream.
+  bool WriteDump(base::PlatformFile minidump_file,
+                 const StabilityReport& report,
+                 const MinidumpInfo& minidump_info);
+
+ private:
+  // An offset within a minidump file. Note: using this type to avoid including
+  // windows.h and relying on the RVA type.
+  using FilePosition = uint32_t;
+
+  // The minidump header is always located at the head.
+  static const FilePosition kHeaderPos = 0U;
+
+  bool WriteDumpImpl(const StabilityReport& report,
+                     const MinidumpInfo& minidump_info);
+
+  bool AppendCrashpadInfo(const crashpad::UUID& client_id,
+                          const crashpad::UUID& report_id,
+                          const std::map<std::string, std::string>& crash_keys);
+
+  bool AppendCrashpadDictionaryEntry(
+      const std::string& key,
+      const std::string& value,
+      std::vector<crashpad::MinidumpSimpleStringDictionaryEntry>* entries);
+
+  // Allocate |size_bytes| within the minidump. On success, |pos| contains the
+  // location of the allocation. Returns true on success, false otherwise.
+  bool Allocate(size_t size_bytes, FilePosition* pos);
+
+  // Seeks |cursor_|. The seek operation is kept separate from the write in
+  // order to make the call explicit. Seek operations can be costly and should
+  // be avoided.
+  bool SeekCursor(FilePosition destination);
+
+  // Write to pre-allocated space.
+  // Note: |pos| must match |cursor_|.
+  template <class DataType>
+  bool Write(FilePosition pos, const DataType& data);
+  bool WriteBytes(FilePosition pos, size_t size_bytes, const char* data);
+
+  // Allocate space for and write the contents of |data|. On success, |pos|
+  // contains the location of the write. Returns true on success, false
+  // otherwise.
+  template <class DataType>
+  bool Append(const DataType& data, FilePosition* pos);
+  template <class DataType>
+  bool AppendVec(const std::vector<DataType>& data, FilePosition* pos);
+  bool AppendUtf8String(base::StringPiece data, FilePosition* pos);
+  bool AppendBytes(base::StringPiece data, FilePosition* pos);
+
+  void RegisterDirectoryEntry(uint32_t stream_type,
+                              FilePosition pos,
+                              uint32_t size);
+
+  // The next allocatable FilePosition.
+  FilePosition next_available_byte_;
+
+  // Storage for the directory during writes.
+  std::vector<MINIDUMP_DIRECTORY> directory_;
+
+  // The file to write to. Only valid within the scope of a call to WriteDump.
+  base::File* minidump_file_;
+
+  DISALLOW_COPY_AND_ASSIGN(PostmortemMinidumpWriter);
+};
+
+PostmortemMinidumpWriter::PostmortemMinidumpWriter()
+    : next_available_byte_(0U), minidump_file_(nullptr) {}
+
+PostmortemMinidumpWriter::~PostmortemMinidumpWriter() {
+  DCHECK_EQ(nullptr, minidump_file_);
+}
+
+bool PostmortemMinidumpWriter::WriteDump(
+    base::PlatformFile minidump_platform_file,
+    const StabilityReport& report,
+    const MinidumpInfo& minidump_info) {
+  DCHECK_NE(base::kInvalidPlatformFile, minidump_platform_file);
+
+  DCHECK_EQ(0U, next_available_byte_);
+  DCHECK(directory_.empty());
+  DCHECK_EQ(nullptr, minidump_file_);
+
+  // We do not own |minidump_platform_file|, but we want to rely on base::File's
+  // API, and so we need to duplicate it.
+  HANDLE duplicated_handle;
+  BOOL duplicate_success = ::DuplicateHandle(
+      ::GetCurrentProcess(), minidump_platform_file, ::GetCurrentProcess(),
+      &duplicated_handle, 0, FALSE, DUPLICATE_SAME_ACCESS);
+  if (!duplicate_success)
+    return false;
+  base::File minidump_file(duplicated_handle);
+  DCHECK(minidump_file.IsValid());
+  minidump_file_ = &minidump_file;
+  DCHECK_EQ(0LL, GetFileOffset(minidump_file_));
+  DCHECK(IsFileEmpty(minidump_file_));
+
+  // Write the minidump, then reset members.
+  bool success = WriteDumpImpl(report, minidump_info);
+  next_available_byte_ = 0U;
+  directory_.clear();
+  minidump_file_ = nullptr;
+
+  return success;
+}
+
+bool PostmortemMinidumpWriter::WriteDumpImpl(
+    const StabilityReport& report,
+    const MinidumpInfo& minidump_info) {
+  // Allocate space for the header and seek the cursor.
+  FilePosition pos = 0U;
+  if (!Allocate(sizeof(MINIDUMP_HEADER), &pos))
+    return false;
+  if (!SeekCursor(sizeof(MINIDUMP_HEADER)))
+    return false;
+  DCHECK_EQ(kHeaderPos, pos);
+
+  // Write the proto to the file.
+  std::string serialized_report;
+  if (!report.SerializeToString(&serialized_report))
+    return false;
+  FilePosition report_pos = 0U;
+  if (!AppendBytes(serialized_report, &report_pos))
+    return false;
+
+  // The directory entry for the stability report's stream.
+  RegisterDirectoryEntry(kStabilityReportStreamType, report_pos,
+                         serialized_report.length());
+
+  // Write mandatory crash keys. These will be read by crashpad and used as
+  // http request parameters for the upload. Keys and values should match
+  // server side configuration.
+  // TODO(manzagop): use product and version from the stability report. The
+  // current executable's values are an (imperfect) proxy.
+  std::map<std::string, std::string> crash_keys = {
+      {"product", minidump_info.product_name + "_Postmortem"},
+      {"version", minidump_info.version_number}};
+  if (!AppendCrashpadInfo(minidump_info.client_id, minidump_info.report_id,
+                          crash_keys))
+    return false;
+
+  // Write the directory.
+  FilePosition directory_pos = 0U;
+  if (!AppendVec(directory_, &directory_pos))
+    return false;
+
+  // Write the header.
+  MINIDUMP_HEADER header;
+  header.Signature = MINIDUMP_SIGNATURE;
+  header.Version = MINIDUMP_VERSION;
+  header.NumberOfStreams = directory_.size();
+  header.StreamDirectoryRva = directory_pos;
+  if (!SeekCursor(0U))
+    return false;
+  return Write(kHeaderPos, header);
+}
+
+bool PostmortemMinidumpWriter::AppendCrashpadInfo(
+    const crashpad::UUID& client_id,
+    const crashpad::UUID& report_id,
+    const std::map<std::string, std::string>& crash_keys) {
+  // Write the crash keys as the contents of a crashpad dictionary.
+  std::vector<crashpad::MinidumpSimpleStringDictionaryEntry> entries;
+  for (const auto& crash_key : crash_keys) {
+    if (!AppendCrashpadDictionaryEntry(crash_key.first, crash_key.second,
+                                       &entries)) {
+      return false;
+    }
+  }
+
+  // Write the dictionary's index.
+  FilePosition dict_pos = 0U;
+  uint32_t entry_count = entries.size();
+  if (entry_count > 0) {
+    if (!Append(entry_count, &dict_pos))
+      return false;
+    FilePosition unused_pos = 0U;
+    if (!AppendVec(entries, &unused_pos))
+      return false;
+  }
+
+  MINIDUMP_LOCATION_DESCRIPTOR simple_annotations = {0};
+  simple_annotations.DataSize = 0U;
+  if (entry_count > 0)
+    simple_annotations.DataSize = next_available_byte_ - dict_pos;
+  // Note: an RVA of 0 indicates the absence of a dictionary.
+  simple_annotations.Rva = dict_pos;
+
+  // Write the crashpad info.
+  crashpad::MinidumpCrashpadInfo crashpad_info;
+  crashpad_info.version = crashpad::MinidumpCrashpadInfo::kVersion;
+  crashpad_info.report_id = report_id;
+  crashpad_info.client_id = client_id;
+  crashpad_info.simple_annotations = simple_annotations;
+  // Note: module_list is left at 0, which means none.
+
+  FilePosition crashpad_pos = 0U;
+  if (!Append(crashpad_info, &crashpad_pos))
+    return false;
+
+  // Append a directory entry for the crashpad info stream.
+  RegisterDirectoryEntry(crashpad::kMinidumpStreamTypeCrashpadInfo,
+                         crashpad_pos, sizeof(crashpad::MinidumpCrashpadInfo));
+
+  return true;
+}
+
+bool PostmortemMinidumpWriter::AppendCrashpadDictionaryEntry(
+    const std::string& key,
+    const std::string& value,
+    std::vector<crashpad::MinidumpSimpleStringDictionaryEntry>* entries) {
+  DCHECK_NE(nullptr, entries);
+
+  FilePosition key_pos = 0U;
+  if (!AppendUtf8String(key, &key_pos))
+    return false;
+  FilePosition value_pos = 0U;
+  if (!AppendUtf8String(value, &value_pos))
+    return false;
+
+  crashpad::MinidumpSimpleStringDictionaryEntry entry = {0};
+  entry.key = key_pos;
+  entry.value = value_pos;
+  entries->push_back(entry);
+
+  return true;
+}
+
+bool PostmortemMinidumpWriter::Allocate(size_t size_bytes, FilePosition* pos) {
+  DCHECK(pos);
+  *pos = next_available_byte_;
+
+  base::CheckedNumeric<FilePosition> next = next_available_byte_;
+  next += size_bytes;
+  if (!next.IsValid())
+    return false;
+
+  next_available_byte_ += size_bytes;
+  return true;
+}
+
+bool PostmortemMinidumpWriter::SeekCursor(FilePosition destination) {
+  DCHECK_NE(nullptr, minidump_file_);
+  DCHECK(minidump_file_->IsValid());
+
+  // Validate the write does not extend past the allocated space.
+  if (destination > next_available_byte_)
+    return false;
+
+  int64_t new_pos = minidump_file_->Seek(base::File::FROM_BEGIN,
+                                         static_cast<int64_t>(destination));
+  return new_pos != -1;
+}
+
+template <class DataType>
+bool PostmortemMinidumpWriter::Write(FilePosition pos, const DataType& data) {
+  static_assert(std::is_trivially_copyable<DataType>::value,
+                "restricted to trivially copyable");
+  return WriteBytes(pos, sizeof(data), reinterpret_cast<const char*>(&data));
+}
+
+bool PostmortemMinidumpWriter::WriteBytes(FilePosition pos,
+                                          size_t size_bytes,
+                                          const char* data) {
+  DCHECK(data);
+  DCHECK_NE(nullptr, minidump_file_);
+  DCHECK(minidump_file_->IsValid());
+  DCHECK_EQ(static_cast<int64_t>(pos), GetFileOffset(minidump_file_));
+
+  // Validate the write does not extend past the next available byte.
+  base::CheckedNumeric<FilePosition> pos_end = pos;
+  pos_end += size_bytes;
+  if (!pos_end.IsValid() || pos_end.ValueOrDie() > next_available_byte_)
+    return false;
+
+  int size_bytes_signed = static_cast<int>(size_bytes);
+  CHECK_LE(0, size_bytes_signed);
+
+  int written_bytes =
+      minidump_file_->WriteAtCurrentPos(data, size_bytes_signed);
+  if (written_bytes < 0)
+    return false;
+  return static_cast<size_t>(written_bytes) == size_bytes;
+}
+
+template <class DataType>
+bool PostmortemMinidumpWriter::Append(const DataType& data, FilePosition* pos) {
+  static_assert(std::is_trivially_copyable<DataType>::value,
+                "restricted to trivially copyable");
+  DCHECK(pos);
+  if (!Allocate(sizeof(data), pos))
+    return false;
+  return Write(*pos, data);
+}
+
+template <class DataType>
+bool PostmortemMinidumpWriter::AppendVec(const std::vector<DataType>& data,
+                                         FilePosition* pos) {
+  static_assert(std::is_trivially_copyable<DataType>::value,
+                "restricted to trivially copyable");
+  DCHECK(!data.empty());
+  DCHECK(pos);
+
+  size_t size_bytes = sizeof(DataType) * data.size();
+  if (!Allocate(size_bytes, pos))
+    return false;
+  return WriteBytes(*pos, size_bytes,
+                    reinterpret_cast<const char*>(&data.at(0)));
+}
+
+bool PostmortemMinidumpWriter::AppendUtf8String(base::StringPiece data,
+                                                FilePosition* pos) {
+  DCHECK(pos);
+  uint32_t string_size = data.size();
+  if (!Append(string_size, pos))
+    return false;
+
+  FilePosition unused_pos = 0U;
+  return AppendBytes(data, &unused_pos);
+}
+
+bool PostmortemMinidumpWriter::AppendBytes(base::StringPiece data,
+                                           FilePosition* pos) {
+  DCHECK(pos);
+  if (!Allocate(data.length(), pos))
+    return false;
+  return WriteBytes(*pos, data.length(), data.data());
+}
+
+void PostmortemMinidumpWriter::RegisterDirectoryEntry(uint32_t stream_type,
+                                                      FilePosition pos,
+                                                      uint32_t size) {
+  MINIDUMP_DIRECTORY entry = {0};
+  entry.StreamType = stream_type;
+  entry.Location.Rva = pos;
+  entry.Location.DataSize = size;
+  directory_.push_back(entry);
+}
+
+}  // namespace
+
+bool WritePostmortemDump(base::PlatformFile minidump_file,
+                         const StabilityReport& report,
+                         const MinidumpInfo& minidump_info) {
+  PostmortemMinidumpWriter writer;
+  return writer.WriteDump(minidump_file, report, minidump_info);
+}
+
+}  // namespace browser_watcher

components/browser_watcher/postmortem_minidump_writer_win_unittest.cc

+// Copyright 2016 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.
+
+#include "components/browser_watcher/postmortem_minidump_writer.h"
+
+#include <windows.h>  // NOLINT
+#include <dbghelp.h>
+
+#include "base/files/file_path.h"
+#include "base/files/file_util.h"
+#include "base/files/scoped_file.h"
+#include "base/files/scoped_temp_dir.h"
+#include "base/win/scoped_handle.h"
+#include "components/browser_watcher/stability_report.pb.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/crashpad/crashpad/snapshot/minidump/process_snapshot_minidump.h"
+#include "third_party/crashpad/crashpad/util/file/file_reader.h"
+#include "third_party/crashpad/crashpad/util/misc/uuid.h"
+
+namespace browser_watcher {
+
+using crashpad::UUID;
+
+const char kProductName[] = "some-product";
+const char kExpectedProductName[] = "some-product_Postmortem";
+const char kVersion[] = "51.0.2704.106";
+
+class WritePostmortemDumpTest : public testing::Test {
+ public:
+  void SetUp() override {
+    testing::Test::SetUp();
+
+    expected_client_id_ = UUID(UUID::InitializeWithNewTag{});
+    expected_report_id_ = UUID(UUID::InitializeWithNewTag{});
+
+    // Create a stability report.
+    // TODO(manzagop): flesh out the report once proto is more detailed.
+    ProcessState* process_state = expected_report_.add_process_states();
+    CodeModule* module = process_state->add_modules();
+    module->set_base_address(1024);
+    module->set_code_file("some_code_file.dll");
+
+    // Write the minidump.
+    ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
+    minidump_path_ = temp_dir_.path().AppendASCII("minidump.dmp");
+  }
+
+  bool WriteDump() {
+    base::win::ScopedHandle file_handle(::CreateFile(
+        minidump_path_.value().c_str(), GENERIC_READ | GENERIC_WRITE,
+        FILE_SHARE_READ | FILE_SHARE_WRITE, nullptr, CREATE_NEW,
+        FILE_ATTRIBUTE_NORMAL, nullptr));
+    if (!file_handle.IsValid())
+      return false;
+
+    MinidumpInfo mindump_info;
+    mindump_info.client_id = expected_client_id_;
+    mindump_info.report_id = expected_report_id_;
+    mindump_info.product_name = kProductName;
+    mindump_info.version_number = kVersion;
+
+    return WritePostmortemDump(file_handle.Get(), expected_report_,
+                               mindump_info);
+  }
+
+  const base::FilePath& minidump_path() { return minidump_path_; }
+  const UUID& expected_client_id() { return expected_client_id_; }
+  const UUID& expected_report_id() { return expected_report_id_; }
+  const StabilityReport& expected_report() { return expected_report_; }
+
+ private:
+  base::ScopedTempDir temp_dir_;
+  base::FilePath minidump_path_;
+  UUID expected_client_id_;
+  UUID expected_report_id_;
+  StabilityReport expected_report_;
+};
+
+TEST_F(WritePostmortemDumpTest, ValidateStabilityReportTest) {
+  ASSERT_TRUE(WriteDump());
+
+  // Read back the minidump to extract the proto.
+  // TODO(manzagop): rely on crashpad for reading the proto once crashpad
+  //     supports it (https://crashpad.chromium.org/bug/10).
+  base::ScopedFILE minidump_file;
+  minidump_file.reset(base::OpenFile(minidump_path(), "rb"));
+  ASSERT_TRUE(minidump_file.get());
+
+  MINIDUMP_HEADER header = {};
+  ASSERT_EQ(1U, fread(&header, sizeof(header), 1, minidump_file.get()));
+  ASSERT_EQ(static_cast<ULONG32>(MINIDUMP_SIGNATURE), header.Signature);
+  ASSERT_EQ(2U, header.NumberOfStreams);
+  RVA directory_rva = header.StreamDirectoryRva;
+
+  MINIDUMP_DIRECTORY directory = {};
+  ASSERT_EQ(0, fseek(minidump_file.get(), directory_rva, SEEK_SET));
+  ASSERT_EQ(1U, fread(&directory, sizeof(directory), 1, minidump_file.get()));
+  ASSERT_EQ(0x4B6B0002U, directory.StreamType);
+  RVA report_rva = directory.Location.Rva;
+  ULONG32 report_size_bytes = directory.Location.DataSize;
+
+  std::string recovered_serialized_report;
+  recovered_serialized_report.resize(report_size_bytes);
+  ASSERT_EQ(0, fseek(minidump_file.get(), report_rva, SEEK_SET));
+  ASSERT_EQ(report_size_bytes, fread(&recovered_serialized_report.at(0), 1,
+                                     report_size_bytes, minidump_file.get()));
+
+  // Validate the recovered report.
+  std::string expected_serialized_report;
+  expected_report().SerializeToString(&expected_serialized_report);
+  ASSERT_EQ(expected_serialized_report, recovered_serialized_report);
+
+  StabilityReport recovered_report;
+  ASSERT_TRUE(recovered_report.ParseFromString(recovered_serialized_report));
+}
+
+TEST_F(WritePostmortemDumpTest, CrashpadCanReadTest) {
+  ASSERT_TRUE(WriteDump());
+
+  // Validate crashpad can read the produced minidump.
+  crashpad::FileReader minidump_file_reader;
+  ASSERT_TRUE(minidump_file_reader.Open(minidump_path()));
+
+  crashpad::ProcessSnapshotMinidump minidump_process_snapshot;
+  ASSERT_TRUE(minidump_process_snapshot.Initialize(&minidump_file_reader));
+
+  // Validate the crashpadinfo.
+  UUID client_id;
+  minidump_process_snapshot.ClientID(&client_id);
+  ASSERT_EQ(expected_client_id(), client_id);
+
+  UUID report_id;
+  minidump_process_snapshot.ReportID(&report_id);
+  ASSERT_EQ(expected_report_id(), report_id);
+
+  std::map<std::string, std::string> parameters =
+      minidump_process_snapshot.AnnotationsSimpleMap();
+  auto it = parameters.find("product");
+  ASSERT_NE(parameters.end(), it);
+  ASSERT_EQ(kExpectedProductName, it->second);
+
+  it = parameters.find("version");
+  ASSERT_NE(parameters.end(), it);
+  ASSERT_EQ(kVersion, it->second);
+}
+
+}  // namespace browser_watcher

components/browser_watcher/stability_report.proto

+// Copyright 2016 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.
+
+syntax = "proto2";
+
+option optimize_for = LITE_RUNTIME;
+
+package browser_watcher;
+
+// The state of the system on which Chrome is running (shutting down, battery
+// level, load, etc.).
+message SystemState {
+  // TODO(manzagop): flesh out.
+}
+
+message CodeModule {
+  // The base address of this code module as it was loaded by the process.
+  optional int64 base_address = 1;
+
+  // The size of the code module.
+  optional int64 size = 2;
+
+  // The path or file name that the code module was loaded from.
+  optional string code_file = 3;
+
+  // An identifying string used to discriminate between multiple versions and
+  // builds of the same code module.  This may contain a uuid, timestamp,
+  // version number, or any combination of this or other information, in an
+  // implementation-defined format.
+  optional string code_identifier = 4;
+
+  // The filename containing debugging information associated with the code
+  // module.  If debugging information is stored in a file separate from the
+  // code module itself (as is the case when .pdb or .dSYM files are used),
+  // this will be different from code_file.  If debugging information is
+  // stored in the code module itself (possibly prior to stripping), this
+  // will be the same as code_file.
+  optional string debug_file = 5;
+
+  // An identifying string similar to code_identifier, but identifies a
+  // specific version and build of the associated debug file.  This may be
+  // the same as code_identifier when the debug_file and code_file are
+  // identical or when the same identifier is used to identify distinct
+  // debug and code files.
+  optional string debug_identifier = 6;
+
+  // A human-readable representation of the code module's version.
+  optional string version = 7;
+}
+
+// The state of a thread.
+message ThreadState {
+  optional string thread_name = 1;
+  // TODO(manzagop): flesh out.
+}
+
+// The state of a process.
+message ProcessState {
+  // Note: likely only a subset of modules of interest (e.g. Chromium's own
+  // modules).
+  repeated CodeModule modules = 1;
+  repeated ThreadState threads = 2;
+  // TODO(manzagop): add experiment state.
+}
+
+// A stability report contains information pertaining to the execution of a
+// single logical instance of a "chrome browser". It is comprised of information
+// about the system state and about the chrome browser's processes.
+message StabilityReport {
+  optional SystemState system_state = 1;
+  // TODO(manzagop): revisit whether a single repeated field should contain all
+  //     processes, or whether it's preferable to have separate fields per type.
+  // TODO(manzagop): add information about the type of process, pid, process
+  //     times (e.g. start time), hierarchical relationships (e.g. parent pid),
+  //     command line, etc.
+  repeated ProcessState process_states = 2;
+}