[ios] Add process uptime to synthetic crash reports

The uptime is only estimate and updated when app gets backgrounded,
battery level changes or similar system notification is posted.

It might be useful to add a timer, which updates up time every few
seconds, but that change will be done in a separate CL.

Bug: 1103752
Change-Id: Ie12af0a259f915181199bd58aa1dbc57758ab60b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2459307
Commit-Queue: Eugene But <eugenebut@chromium.org>
Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#815350}

ios/chrome/browser/crash_report/synthetic_crash_report_util.mm

@@ -101,6 +101,13 @@ void CreateSyntheticCrashReportForUte(
         base::SysNSStringToUTF8(previous_session.reportParameterURLs[key]));
   }
 
+  if (previous_session.sessionStartTime && previous_session.sessionEndTime) {
+    NSTimeInterval uptime = [previous_session.sessionEndTime
+        timeIntervalSinceDate:previous_session.sessionStartTime];
+    AppendConfig(config, "BreakpadProcessUpTime",
+                 base::NumberToString(static_cast<long>(uptime * 1000)));
+  }
+
   // Write empty minidump file, as Breakpad can't upload config without the
   // minidump.
   base::File minidump_file(

ios/chrome/browser/crash_report/synthetic_crash_report_util_unittest.mm

@@ -42,6 +42,10 @@ TEST_F(SyntheticCrashReportUtilTest, CreateSyntheticCrashReportForUte) {
   previous_session.terminatedDuringSessionRestoration = YES;
   NSString* const kURL = @"URL";
   previous_session.reportParameterURLs = @{@"url" : kURL};
+  previous_session.sessionStartTime = [NSDate date];
+  const NSTimeInterval kUptimeMs = 5000;
+  previous_session.sessionEndTime = [previous_session.sessionStartTime
+      dateByAddingTimeInterval:kUptimeMs / 1000];
 
   // Create crash report.
   base::ScopedTempDir temp_dir;
@@ -98,7 +102,7 @@ TEST_F(SyntheticCrashReportUtilTest, CreateSyntheticCrashReportForUte) {
 
   // Verify config file content. Config file has the following format:
   // <Key1>\n<Value1Length>\n<Value1>\n...<KeyN>\n<ValueNLength>\n<ValueN>
-  ASSERT_EQ(42U, config_lines.size())
+  ASSERT_EQ(45U, config_lines.size())
       << "<content>" << config_content << "</content>";
 
   EXPECT_EQ("MinidumpDir", config_lines[0]);
@@ -167,6 +171,11 @@ TEST_F(SyntheticCrashReportUtilTest, CreateSyntheticCrashReportForUte) {
   EXPECT_EQ(base::NumberToString(kURL.length), config_lines[40]);
   EXPECT_EQ(base::SysNSStringToUTF8(kURL), config_lines[41]);
 
+  EXPECT_EQ("BreakpadProcessUpTime", config_lines[42]);
+  EXPECT_EQ(base::NumberToString(base::NumberToString(kUptimeMs).size()),
+            config_lines[43]);
+  EXPECT_EQ(base::NumberToString(kUptimeMs), config_lines[44]);
+
   // Read minidump file. It must be empty as there is no stack trace, but
   // Breakpad will not upload config without minidump file.
   base::File minidump_file(minidump_file_path,

ios/chrome/browser/metrics/previous_session_info.h

@@ -110,6 +110,11 @@ enum class DeviceBatteryState {
 // is available.
 @property(nonatomic, strong, readonly) NSString* OSVersion;
 
+// The date time at which recording for the previous sesion has started. Note
+// that recording usually starts soon after startup, but not exactly at the
+// startup.
+@property(nonatomic, strong, readonly) NSDate* sessionStartTime;
+
 // The time at which the previous sesion ended. Note that this is only an
 // estimate and is updated whenever another value of the receiver is updated.
 @property(nonatomic, strong, readonly) NSDate* sessionEndTime;

ios/chrome/browser/metrics/previous_session_info.mm

@@ -76,6 +76,8 @@ NSString* const kPreviousSessionInfoBatteryLevel =
 //   the device battery state.
 NSString* const kPreviousSessionInfoBatteryState =
     @"PreviousSessionInfoBatteryState";
+// - The (Date) of the recording start.
+NSString* const kPreviousSessionInfoStartTime = @"PreviousSessionInfoStartTime";
 // - The (Date) of the estimated end of the session.
 NSString* const kPreviousSessionInfoEndTime = @"PreviousSessionInfoEndTime";
 // - The (string) OS version.
@@ -130,6 +132,7 @@ NSString* const kPreviousSessionInfoURLs = @"PreviousSessionInfoURLs";
 @property(nonatomic, assign) BOOL isMultiWindowEnabledSession;
 @property(nonatomic, assign) BOOL OSRestartedAfterPreviousSession;
 @property(nonatomic, strong) NSString* OSVersion;
+@property(nonatomic, strong) NSDate* sessionStartTime;
 @property(nonatomic, strong) NSDate* sessionEndTime;
 @property(nonatomic, assign) BOOL terminatedDuringSessionRestoration;
 @property(nonatomic, strong) NSMutableSet<NSString*>* connectedSceneSessionsIDs;
@@ -177,6 +180,8 @@ static PreviousSessionInfo* gSharedInstance = nil;
         [defaults floatForKey:kPreviousSessionInfoBatteryLevel];
     gSharedInstance.deviceThermalState = static_cast<DeviceThermalState>(
         [defaults integerForKey:kPreviousSessionInfoThermalState]);
+    gSharedInstance.sessionStartTime =
+        [defaults objectForKey:kPreviousSessionInfoStartTime];
     gSharedInstance.sessionEndTime =
         [defaults objectForKey:kPreviousSessionInfoEndTime];
 
@@ -266,6 +271,8 @@ static PreviousSessionInfo* gSharedInstance = nil;
       removeObjectForKey:previous_session_info_constants::
                              kDidSeeMemoryWarningShortlyBeforeTerminating];
 
+  [defaults setObject:[NSDate date] forKey:kPreviousSessionInfoStartTime];
+
   [[NSNotificationCenter defaultCenter]
       addObserver:self
          selector:@selector(updateApplicationState)

ios/chrome/browser/metrics/previous_session_info_private.h

@@ -18,6 +18,8 @@
     previous_session_info_constants::DeviceBatteryState deviceBatteryState;
 @property(nonatomic, assign) BOOL OSRestartedAfterPreviousSession;
 @property(nonatomic, copy) NSString* OSVersion;
+@property(nonatomic, strong) NSDate* sessionStartTime;
+@property(nonatomic, strong) NSDate* sessionEndTime;
 @property(nonatomic, assign) BOOL terminatedDuringSessionRestoration;
 @property(nonatomic, strong) NSMutableSet<NSString*>* connectedSceneSessionsIDs;
 @property(nonatomic, copy)