[iOS] Set breadcrumb events from previous sessions on the crash report

Bug: 1117667
Change-Id: I3f2fb6a013697ad414c7d5458d0bebb68ee2749b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2363702
Commit-Queue: Mike Dougherty <michaeldo@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#800016}

ios/chrome/app/main_controller.mm

@@ -974,6 +974,7 @@ void MainControllerAuthenticationServiceDelegate::ClearBrowsingData(
         BreadcrumbManagerKeyedServiceFactory::GetForBrowserState(
             strongSelf.mainBrowserState)
             ->SetPreviousEvents(events);
+        breakpad::SetPreviousSessionEvents(events);
 
         // Notify persistent breadcrumb service to clear old breadcrumbs and
         // start storing breadcrumbs for this session.

ios/chrome/browser/crash_report/crash_report_helper.h

@@ -5,6 +5,9 @@
 #ifndef IOS_CHROME_BROWSER_CRASH_REPORT_CRASH_REPORT_HELPER_H_
 #define IOS_CHROME_BROWSER_CRASH_REPORT_CRASH_REPORT_HELPER_H_
 
+#include <string>
+#include <vector>
+
 @class NSString;
 
 class BreadcrumbManager;
@@ -67,6 +70,9 @@ void MonitorBreadcrumbManagerService(
 void StopMonitoringBreadcrumbManagerService(
     BreadcrumbManagerKeyedService* breadcrumb_manager_service);
 
+// Sets breadcrumb events associated with the previous application session.
+void SetPreviousSessionEvents(const std::vector<std::string>& events);
+
 }  // namespace breakpad
 
 #endif  // IOS_CHROME_BROWSER_CRASH_REPORT_CRASH_REPORT_HELPER_H_

ios/chrome/browser/crash_report/crash_report_helper.mm

@@ -258,4 +258,9 @@ void StopMonitoringBreadcrumbManagerService(
       stopObservingBreadcrumbManagerService:breadcrumb_manager_service];
 }
 
+void SetPreviousSessionEvents(const std::vector<std::string>& events) {
+  [[CrashReporterBreadcrumbObserver uniqueInstance]
+      setPreviousSessionEvents:events];
+}
+
 }  // namespace breakpad

ios/chrome/browser/crash_report/crash_reporter_breadcrumb_observer.h

@@ -21,6 +21,9 @@
 // Creates a singleton instance.
 + (CrashReporterBreadcrumbObserver*)uniqueInstance;
 
+// Sets breadcrumb events associated with the previous application session.
+- (void)setPreviousSessionEvents:(const std::vector<std::string>&)events;
+
 // Starts collecting breadcrumb events logged to |breadcrumbManager|.
 - (void)observeBreadcrumbManager:(BreadcrumbManager*)breadcrumbManager;
 

ios/chrome/browser/crash_report/crash_reporter_breadcrumb_observer.mm

@@ -4,6 +4,7 @@
 
 #include "ios/chrome/browser/crash_report/crash_reporter_breadcrumb_observer.h"
 
+#include "base/strings/sys_string_conversions.h"
 #include "ios/chrome/browser/crash_report/breadcrumbs/breadcrumb_manager.h"
 #import "ios/chrome/browser/crash_report/breadcrumbs/breadcrumb_manager_observer_bridge.h"
 #include "ios/chrome/browser/crash_report/crash_keys_helper.h"
@@ -30,6 +31,10 @@
   // in order to reduce overall memory usage.
   NSMutableString* _breadcrumbs;
 }
+
+// Updates the breadcrumbs stored in the crash log.
+- (void)updateBreadcrumbEventsCrashKey;
+
 @end
 
 @implementation CrashReporterBreadcrumbObserver
@@ -73,13 +78,17 @@
   _breadcrumbManagerServiceObservers[breadcrumbManagerService] = nullptr;
 }
 
-#pragma mark - BreadcrumbManagerObserving protocol
-
-- (void)breadcrumbManager:(BreadcrumbManager*)manager
-              didAddEvent:(NSString*)event {
+- (void)setPreviousSessionEvents:(const std::vector<std::string>&)events {
+  for (auto event_it = events.rbegin(); event_it != events.rend(); ++event_it) {
+    NSString* event = base::SysUTF8ToNSString(*event_it);
     NSString* eventWithSeperator = [NSString stringWithFormat:@"%@\n", event];
-  [_breadcrumbs insertString:eventWithSeperator atIndex:0];
+    [_breadcrumbs appendString:eventWithSeperator];
+  }
+
+  [self updateBreadcrumbEventsCrashKey];
+}
 
+- (void)updateBreadcrumbEventsCrashKey {
   if (_breadcrumbs.length > kMaxBreadcrumbsDataLength) {
     NSRange trimRange =
         NSMakeRange(kMaxBreadcrumbsDataLength,
@@ -90,4 +99,14 @@
   crash_keys::SetBreadcrumbEvents(_breadcrumbs);
 }
 
+#pragma mark - BreadcrumbManagerObserving protocol
+
+- (void)breadcrumbManager:(BreadcrumbManager*)manager
+              didAddEvent:(NSString*)event {
+  NSString* eventWithSeperator = [NSString stringWithFormat:@"%@\n", event];
+  [_breadcrumbs insertString:eventWithSeperator atIndex:0];
+
+  [self updateBreadcrumbEventsCrashKey];
+}
+
 @end