[Breadcrumbs] Use 6 product data keys for Breadcrumbs

Most crashes with known steps to repro require 4 product data keys to
fit all steps. Users will likely do unnecessary steps between required
steps, so using 2 extra keys should allow to accommodate for all steps.

Bug: 1046223
Change-Id: Ia6b97453822a2ab7e6b80cc11488f9f0f91fc949
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2089720
Commit-Queue: Eugene But <eugenebut@chromium.org>
Auto-Submit: Eugene But <eugenebut@chromium.org>
Reviewed-by: Mike Dougherty <michaeldo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#748911}

ios/chrome/browser/crash_report/breakpad_helper.mm

@@ -371,7 +371,8 @@ void RemoveGridToVisibleTabAnimation() {
 }
 
 void SetBreadcrumbEvents(NSArray* breadcrumbs) {
-  DCHECK_LE(breadcrumbs.count, 4U);
+  DCHECK_GT(breadcrumbs.count, 0U);
+  DCHECK_LE(breadcrumbs.count, 6U);
   for (NSUInteger i = 0; i < breadcrumbs.count; i++) {
     NSString* key = [NSString stringWithFormat:kBreadcrumbs, i];
     AddReportParameter(key, breadcrumbs[i], /*async=*/true);

ios/chrome/browser/crash_report/breakpad_helper_unittest.mm

@@ -3,6 +3,8 @@
 // found in the LICENSE file.
 
 #import "ios/chrome/browser/crash_report/breakpad_helper.h"
+
+#include "ios/chrome/browser/crash_report/crash_report_helper.h"
 #include "ios/chrome/browser/crash_report/main_thread_freeze_detector.h"
 #import "ios/chrome/test/ocmock/OCMockObject+BreakpadControllerTesting.h"
 #import "ios/testing/scoped_block_swizzler.h"
@@ -82,7 +84,12 @@ TEST_F(BreakpadHelperTest, CrashReportUserApplicationStateAllKeys) {
   while (breadcrumbs.length < 255) {
     [breadcrumbs appendString:@"12:01 Fake Breadcrumb Event/n"];
   }
-  breakpad_helper::SetBreadcrumbEvents(@[ breadcrumbs, breadcrumbs ]);
+
+  NSMutableArray* events = [[NSMutableArray alloc] init];
+  for (int i = 0; i < breakpad::kBreadcrumbsKeyCount; i++) {
+    [events addObject:breadcrumbs];
+  }
+  breakpad_helper::SetBreadcrumbEvents(events);
 }
 
 TEST_F(BreakpadHelperTest, GetCrashReportCount) {

ios/chrome/browser/crash_report/crash_report_helper.h

@@ -18,6 +18,12 @@ class WebStateList;
 
 namespace breakpad {
 
+// Number of product data keys to use for breadcrumbs. Each product key allows
+// to upload limited amount of data (kMaxProductDataLength), so having
+// multiple keys makes breadcrumbs more useful by having access to more
+// breadcrumbs on crash reports.
+extern const int kBreadcrumbsKeyCount;
+
 // Monitors the urls loaded by |web_state| to allow crash reports to contain the
 // current loading url.
 void MonitorURLsForWebState(web::WebState* web_state);

ios/chrome/browser/crash_report/crash_report_helper.mm

@@ -37,6 +37,12 @@
 #error "This file requires ARC support."
 #endif
 
+namespace breakpad {
+// IMPORTANT: be careful if ever increasing this value, Breakpad reports have an
+// overall size limit
+const int kBreadcrumbsKeyCount = 6;
+}
+
 // WebStateListObserver that allows loaded urls to be sent to the crash server.
 @interface CrashReporterURLObserver
     : NSObject <WebStateListObserving, CRWWebStateObserver> {
@@ -442,6 +448,8 @@ void ClearStateForWebStateList(WebStateList* web_state_list) {
 void MonitorBreadcrumbManager(BreadcrumbManager* breadcrumb_manager) {
   [[CrashReporterBreadcrumbObserver uniqueInstance]
       observeBreadcrumbManager:breadcrumb_manager];
+  [CrashReporterBreadcrumbObserver uniqueInstance].breadcrumbsKeyCount =
+      kBreadcrumbsKeyCount;
 }
 
 void StopMonitoringBreadcrumbManager(BreadcrumbManager* breadcrumb_manager) {

ios/chrome/browser/crash_report/crash_reporter_breadcrumb_observer.h

@@ -24,6 +24,9 @@ extern const int kMaxProductDataLength;
 // Creates a singleton instance.
 + (CrashReporterBreadcrumbObserver*)uniqueInstance;
 
+// Number of product data keys to use for breadcrumbs.
+@property(nonatomic) NSUInteger breadcrumbsKeyCount;
+
 // Starts collecting breadcrumb events logged to |breadcrumbManager|.
 - (void)observeBreadcrumbManager:(BreadcrumbManager*)breadcrumbManager;
 

ios/chrome/browser/crash_report/crash_reporter_breadcrumb_observer.mm

@@ -12,15 +12,6 @@
 #error "This file requires ARC support."
 #endif
 
-namespace {
-// IMPORTANT: the value of this constant should not exceed 4.
-// Number of product data keys to use for breadcrumbs. Each product key allows
-// to upload limited amount of data (kMaxProductDataLength), so having
-// multiple keys makes breadcrumbs more useful by having access to more
-// breadcrumbs on crash reports.
-const int kBreadcrumbsKeyCount = 2;
-}
-
 const int kMaxProductDataLength = 255;
 
 @interface CrashReporterBreadcrumbObserver () {
@@ -91,7 +82,7 @@ const int kMaxProductDataLength = 255;
   [_breadcrumbs insertString:eventWithSeperator atIndex:0];
 
   NSUInteger maxBreadcrumbsLength =
-      kBreadcrumbsKeyCount * kMaxProductDataLength;
+      self.breadcrumbsKeyCount * kMaxProductDataLength;
   if (_breadcrumbs.length > maxBreadcrumbsLength) {
     NSRange trimRange = NSMakeRange(maxBreadcrumbsLength,
                                     _breadcrumbs.length - maxBreadcrumbsLength);
@@ -100,8 +91,8 @@ const int kMaxProductDataLength = 255;
 
   // Cut breadcrumbs strings into multiple pieces and upload with separate keys.
   NSMutableArray* breadcrumbs =
-      [[NSMutableArray alloc] initWithCapacity:kBreadcrumbsKeyCount];
-  for (NSUInteger i = 0; i < kBreadcrumbsKeyCount &&
+      [[NSMutableArray alloc] initWithCapacity:self.breadcrumbsKeyCount];
+  for (NSUInteger i = 0; i < self.breadcrumbsKeyCount &&
                          (i * kMaxProductDataLength) < _breadcrumbs.length;
        i++) {
     NSUInteger location = i * kMaxProductDataLength;

ios/chrome/browser/crash_report/crash_reporter_breadcrumb_observer_unittest.mm

@@ -12,6 +12,7 @@
 #include "ios/chrome/browser/crash_report/breadcrumbs/breadcrumb_manager_keyed_service.h"
 #include "ios/chrome/browser/crash_report/breadcrumbs/breadcrumb_manager_keyed_service_factory.h"
 #import "ios/chrome/browser/crash_report/breakpad_helper.h"
+#include "ios/chrome/browser/crash_report/crash_report_helper.h"
 #import "ios/chrome/test/ocmock/OCMockObject+BreakpadControllerTesting.h"
 #import "ios/testing/scoped_block_swizzler.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -100,6 +101,8 @@ TEST_F(CrashReporterBreadcrumbObserverTest, EventsAttachedToCrashReport) {
           chrome_browser_state_.get());
   CrashReporterBreadcrumbObserver* crash_reporter_breadcrumb_observer =
       [[CrashReporterBreadcrumbObserver alloc] init];
+  crash_reporter_breadcrumb_observer.breadcrumbsKeyCount =
+      breakpad::kBreadcrumbsKeyCount;
   [crash_reporter_breadcrumb_observer
       observeBreadcrumbManagerService:breadcrumb_service];
 
@@ -134,6 +137,8 @@ TEST_F(CrashReporterBreadcrumbObserverTest, MultipleKeysAttachedToCrashReport) {
           chrome_browser_state_.get());
   CrashReporterBreadcrumbObserver* crash_reporter_breadcrumb_observer =
       [[CrashReporterBreadcrumbObserver alloc] init];
+  crash_reporter_breadcrumb_observer.breadcrumbsKeyCount =
+      breakpad::kBreadcrumbsKeyCount;
   [crash_reporter_breadcrumb_observer
       observeBreadcrumbManagerService:breadcrumb_service];
 
@@ -179,6 +184,8 @@ TEST_F(CrashReporterBreadcrumbObserverTest, ProductDataOverflow) {
           chrome_browser_state_.get());
   CrashReporterBreadcrumbObserver* crash_reporter_breadcrumb_observer =
       [[CrashReporterBreadcrumbObserver alloc] init];
+  // Testing with 2 keys requires less code and complexity.
+  crash_reporter_breadcrumb_observer.breadcrumbsKeyCount = 2;
   [crash_reporter_breadcrumb_observer
       observeBreadcrumbManagerService:breadcrumb_service];
 
@@ -244,6 +251,8 @@ TEST_F(CrashReporterBreadcrumbObserverTest,
           chrome_browser_state_.get());
   CrashReporterBreadcrumbObserver* crash_reporter_breadcrumb_observer =
       [[CrashReporterBreadcrumbObserver alloc] init];
+  crash_reporter_breadcrumb_observer.breadcrumbsKeyCount =
+      breakpad::kBreadcrumbsKeyCount;
   [crash_reporter_breadcrumb_observer
       observeBreadcrumbManagerService:breadcrumb_service];