[Mac] Add field trial tuples to breakpad crash reports.

This is the Mac-side of http://codereview.chromium.org/9432033.

BUG=134741
TEST=Mac crash dumps show experiment chunks.

Review URL: https://chromiumcodereview.appspot.com/10661057

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@144929 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 136 insertions, 25 deletions

diff --git a/chrome/common/child_process_logging.h b/chrome/common/child_process_logging.h
index cc4ecad..010df4b 100644
--- a/chrome/common/child_process_logging.h
+++ b/chrome/common/child_process_logging.h
@@ -31,6 +31,11 @@ static const int kMaxReportedActiveExtensions = 10;
 // dependency.
 static const int kMaxReportedExperimentChunks = 15;
 
+// The maximum size of an experiment chunk. This size was picked to be
+// consistent between platforms and the value was chosen from the Windows
+// limit of google_breakpad::CustomInfoEntry::kValueMaxLength.
+static const size_t kMaxExperimentChunkSize = 64;
+
 // The maximum number of prn-info-* records.
 static const size_t kMaxReportedPrinterRecords = 4;
 
diff --git a/chrome/common/child_process_logging_mac.mm b/chrome/common/child_process_logging_mac.mm
index 3c9ac6c..e514c87 100644
--- a/chrome/common/child_process_logging_mac.mm
+++ b/chrome/common/child_process_logging_mac.mm
@@ -13,6 +13,7 @@
 #include "base/stringprintf.h"
 #include "base/sys_string_conversions.h"
 #include "base/utf_string_conversions.h"
+#include "chrome/common/metrics/experiments_helper.h"
 #include "chrome/installer/util/google_update_settings.h"
 #include "content/public/common/gpu_info.h"
 #include "googleurl/src/gurl.h"
@@ -220,8 +221,31 @@ void SetCommandLine(const CommandLine* command_line) {
   }
 }
 
-void SetExperimentList(const std::vector<string16>& state) {
-  // TODO(mad): Implement this.
+void SetExperimentList(const std::vector<string16>& experiments) {
+  // These should match the corresponding strings in breakpad_win.cc.
+  NSString* const kNumExperimentsKey = @"num-experiments";
+  NSString* const kExperimentChunkFormat = @"experiment-chunk-%zu";  // 1-based.
+
+  std::vector<string16> chunks;
+  experiments_helper::GenerateExperimentChunks(experiments, &chunks);
+
+  // Store up to |kMaxReportedExperimentChunks| chunks.
+  for (size_t i = 0; i < kMaxReportedExperimentChunks; ++i) {
+    NSString* key = [NSString stringWithFormat:kExperimentChunkFormat, i + 1];
+    if (i < chunks.size()) {
+      NSString* value = base::SysUTF16ToNSString(chunks[i]);
+      SetCrashKeyValue(key, value);
+    } else {
+      ClearCrashKey(key);
+    }
+  }
+
+  // Make note of the total number of experiments, which may be greater than
+  // what was able to fit in |kMaxReportedExperimentChunks|. This is useful
+  // when correlating stability with the number of experiments running
+  // simultaneously.
+  SetCrashKeyValue(kNumExperimentsKey,
+                   [NSString stringWithFormat:@"%zu", experiments.size()]);
 }
 
 void SetChannel(const std::string& channel) {
diff --git a/chrome/common/metrics/experiments_helper.cc b/chrome/common/metrics/experiments_helper.cc
index 3bc3aee..0fb6fa6 100644
--- a/chrome/common/metrics/experiments_helper.cc
+++ b/chrome/common/metrics/experiments_helper.cc
@@ -4,6 +4,7 @@
 
 #include "chrome/common/metrics/experiments_helper.h"
 
+#include <map>
 #include <vector>
 
 #include "base/memory/singleton.h"
@@ -130,6 +131,25 @@ chrome_variations::ID GetGoogleVariationID(const std::string& trial_name,
       MakeSelectedGroupId(trial_name, group_name));
 }
 
+void GenerateExperimentChunks(const std::vector<string16>& experiments,
+                              std::vector<string16>* chunks) {
+  string16 current_chunk;
+  for (size_t i = 0; i < experiments.size(); ++i) {
+    const size_t needed_length =
+        (current_chunk.empty() ? 1 : 0) + experiments[i].length();
+    if (current_chunk.length() + needed_length > kMaxExperimentChunkSize) {
+      chunks->push_back(current_chunk);
+      current_chunk = experiments[i];
+    } else {
+      if (!current_chunk.empty())
+        current_chunk.push_back(',');
+      current_chunk += experiments[i];
+    }
+  }
+  if (!current_chunk.empty())
+    chunks->push_back(current_chunk);
+}
+
 void SetChildProcessLoggingExperimentList() {
   std::vector<SelectedGroupId> name_group_ids;
   GetFieldTrialSelectedGroupIds(&name_group_ids);
diff --git a/chrome/common/metrics/experiments_helper.h b/chrome/common/metrics/experiments_helper.h
index 71d1ed8..e821d4b 100644
--- a/chrome/common/metrics/experiments_helper.h
+++ b/chrome/common/metrics/experiments_helper.h
@@ -10,6 +10,7 @@
 #include <vector>
 
 #include "base/metrics/field_trial.h"
+#include "base/string16.h"
 #include "chrome/common/metrics/variation_ids.h"
 
 // This namespace provides various helpers that extend the functionality around
@@ -101,6 +102,11 @@ void AssociateGoogleVariationIDForce(const std::string& trial_name,
 chrome_variations::ID GetGoogleVariationID(const std::string& trial_name,
                                            const std::string& group_name);
 
+// Generates experiment chunks from |experiment_strings| that are suitable for
+// crash reporting.
+void GenerateExperimentChunks(const std::vector<string16>& experiment_strings,
+                              std::vector<string16>* chunks);
+
 // Get the current set of chosen FieldTrial groups (aka experiments) and send
 // them to the child process logging module so it can save it for crash dumps.
 void SetChildProcessLoggingExperimentList();
@@ -117,6 +123,6 @@ void TestGetFieldTrialSelectedGroupIdsForSelectedGroups(
 
 uint32 TestHashName(const std::string& name);
 
-}
+}  // namespace testing
 
 #endif  // CHROME_COMMON_METRICS_EXPERIMENTS_HELPER_H_
diff --git a/chrome/common/metrics/experiments_helper_unittest.cc b/chrome/common/metrics/experiments_helper_unittest.cc
index b961a7d..268d25a 100644
--- a/chrome/common/metrics/experiments_helper_unittest.cc
+++ b/chrome/common/metrics/experiments_helper_unittest.cc
@@ -10,17 +10,19 @@
 #include "base/message_loop.h"
 #include "base/metrics/field_trial.h"
 #include "base/time.h"
+#include "base/utf_string_conversions.h"
 #include "chrome/common/metrics/experiments_helper.h"
 #include "content/public/test/test_browser_thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+namespace experiments_helper {
+
 namespace {
 
 // Convenience helper to retrieve the chrome_variations::ID for a FieldTrial.
 // Note that this will do the group assignment in |trial| if not already done.
 chrome_variations::ID GetIDForTrial(base::FieldTrial* trial) {
-  return experiments_helper::GetGoogleVariationID(trial->name(),
-                                                  trial->group_name());
+  return GetGoogleVariationID(trial->name(), trial->group_name());
 }
 
 }  // namespace
@@ -72,8 +74,7 @@ TEST_F(ExperimentsHelperTest, HashName) {
 }
 
 TEST_F(ExperimentsHelperTest, GetFieldTrialSelectedGroups) {
-  typedef std::set<experiments_helper::SelectedGroupId,
-      experiments_helper::SelectedGroupIdCompare> SelectedGroupIdSet;
+  typedef std::set<SelectedGroupId, SelectedGroupIdCompare> SelectedGroupIdSet;
   std::string trial_one("trial one");
   std::string group_one("group one");
   std::string trial_two("trial two");
@@ -91,7 +92,7 @@ TEST_F(ExperimentsHelperTest, GetFieldTrialSelectedGroups) {
 
   // Create our expected groups of IDs.
   SelectedGroupIdSet expected_groups;
-  experiments_helper::SelectedGroupId name_group_id;
+  SelectedGroupId name_group_id;
   name_group_id.name = testing::TestHashName(trial_one);
   name_group_id.group = testing::TestHashName(group_one);
   expected_groups.insert(name_group_id);
@@ -99,7 +100,7 @@ TEST_F(ExperimentsHelperTest, GetFieldTrialSelectedGroups) {
   name_group_id.group = testing::TestHashName(group_two);
   expected_groups.insert(name_group_id);
 
-  std::vector<experiments_helper::SelectedGroupId> selected_group_ids;
+  std::vector<SelectedGroupId> selected_group_ids;
   testing::TestGetFieldTrialSelectedGroupIdsForSelectedGroups(
       selected_groups, &selected_group_ids);
   EXPECT_EQ(2U, selected_group_ids.size());
@@ -137,9 +138,9 @@ TEST_F(ExperimentsHelperTest, DisableAfterInitialization) {
       base::FieldTrialList::FactoryGetFieldTrial("trial", 100, default_name,
                                                  next_year_, 12, 12, NULL));
   trial->AppendGroup(non_default_name, 100);
-  experiments_helper::AssociateGoogleVariationID(
+  AssociateGoogleVariationID(
       trial->name(), default_name, chrome_variations::kTestValueA);
-  experiments_helper::AssociateGoogleVariationID(
+  AssociateGoogleVariationID(
       trial->name(), non_default_name, chrome_variations::kTestValueB);
   ASSERT_EQ(non_default_name, trial->group_name());
   ASSERT_EQ(chrome_variations::kTestValueB, GetIDForTrial(trial.get()));
@@ -158,9 +159,9 @@ TEST_F(ExperimentsHelperTest, AssociateGoogleVariationID) {
   int winner_group = trial_true->AppendGroup(winner, 10);
 
   // Set GoogleVariationIDs so we can verify that they were chosen correctly.
-  experiments_helper::AssociateGoogleVariationID(
+  AssociateGoogleVariationID(
       trial_true->name(), default_name1, chrome_variations::kTestValueA);
-  experiments_helper::AssociateGoogleVariationID(
+  AssociateGoogleVariationID(
       trial_true->name(), winner, chrome_variations::kTestValueB);
 
   EXPECT_EQ(winner_group, trial_true->group());
@@ -174,9 +175,9 @@ TEST_F(ExperimentsHelperTest, AssociateGoogleVariationID) {
   const std::string loser = "ALoser";
   int loser_group = trial_false->AppendGroup(loser, 0);
 
-  experiments_helper::AssociateGoogleVariationID(
+  AssociateGoogleVariationID(
       trial_false->name(), default_name2, chrome_variations::kTestValueA);
-  experiments_helper::AssociateGoogleVariationID(
+  AssociateGoogleVariationID(
       trial_false->name(), loser, chrome_variations::kTestValueB);
 
   EXPECT_NE(loser_group, trial_false->group());
@@ -203,17 +204,72 @@ TEST_F(ExperimentsHelperTest, NoAssociation) {
 // Ensure that the AssociateGoogleVariationIDForce works as expected.
 TEST_F(ExperimentsHelperTest, ForceAssociation) {
   EXPECT_EQ(chrome_variations::kEmptyID,
-      experiments_helper::GetGoogleVariationID("trial", "group"));
-  experiments_helper::AssociateGoogleVariationID("trial", "group",
-      chrome_variations::kTestValueA);
+            GetGoogleVariationID("trial", "group"));
+  AssociateGoogleVariationID("trial", "group",
+                             chrome_variations::kTestValueA);
   EXPECT_EQ(chrome_variations::kTestValueA,
-      experiments_helper::GetGoogleVariationID("trial", "group"));
-  experiments_helper::AssociateGoogleVariationID("trial", "group",
-      chrome_variations::kTestValueB);
+            GetGoogleVariationID("trial", "group"));
+  AssociateGoogleVariationID("trial", "group", chrome_variations::kTestValueB);
   EXPECT_EQ(chrome_variations::kTestValueA,
-      experiments_helper::GetGoogleVariationID("trial", "group"));
-  experiments_helper::AssociateGoogleVariationIDForce("trial", "group",
-      chrome_variations::kTestValueB);
+            GetGoogleVariationID("trial", "group"));
+  AssociateGoogleVariationIDForce("trial", "group",
+                                  chrome_variations::kTestValueB);
   EXPECT_EQ(chrome_variations::kTestValueB,
-      experiments_helper::GetGoogleVariationID("trial", "group"));
+            GetGoogleVariationID("trial", "group"));
 }
+
+TEST_F(ExperimentsHelperTest, GenerateExperimentChunks) {
+  const char* kExperimentStrings[] = {
+      "1d3048f1-9de009d0",
+      "cd73da34-cf196cb",
+      "6214fa18-9e6dc24d",
+      "4dcb0cd6-d31c4ca1",
+      "9d5bce6-30d7d8ac",
+  };
+  const char* kExpectedChunks1[] = {
+      "1d3048f1-9de009d0",
+  };
+  const char* kExpectedChunks2[] = {
+      "1d3048f1-9de009d0,cd73da34-cf196cb",
+  };
+  const char* kExpectedChunks3[] = {
+      "1d3048f1-9de009d0,cd73da34-cf196cb,6214fa18-9e6dc24d",
+  };
+  const char* kExpectedChunks4[] = {
+      "1d3048f1-9de009d0,cd73da34-cf196cb,6214fa18-9e6dc24d",
+      "4dcb0cd6-d31c4ca1",
+  };
+  const char* kExpectedChunks5[] = {
+      "1d3048f1-9de009d0,cd73da34-cf196cb,6214fa18-9e6dc24d",
+      "4dcb0cd6-d31c4ca1,9d5bce6-30d7d8ac",
+  };
+
+  struct {
+    size_t strings_length;
+    size_t expected_chunks_length;
+    const char** expected_chunks;
+  } cases[] = {
+    { 0, 0, NULL },
+    { 1, arraysize(kExpectedChunks1), kExpectedChunks1 },
+    { 2, arraysize(kExpectedChunks2), kExpectedChunks2 },
+    { 3, arraysize(kExpectedChunks3), kExpectedChunks3 },
+    { 4, arraysize(kExpectedChunks4), kExpectedChunks4 },
+    { 5, arraysize(kExpectedChunks5), kExpectedChunks5 },
+  };
+
+  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i) {
+    ASSERT_LE(cases[i].strings_length, arraysize(kExperimentStrings));
+
+    std::vector<string16> experiments;
+    for (size_t j = 0; j < cases[i].strings_length; ++j)
+      experiments.push_back(UTF8ToUTF16(kExperimentStrings[j]));
+
+    std::vector<string16> chunks;
+    GenerateExperimentChunks(experiments, &chunks);
+    ASSERT_EQ(cases[i].expected_chunks_length, chunks.size());
+    for (size_t j = 0; j < chunks.size(); ++j)
+      EXPECT_EQ(UTF8ToUTF16(cases[i].expected_chunks[j]), chunks[j]);
+  }
+}
+
+}  // namespace experiments_helper