Fix hang-report field in hang crash reports.

hang-report field was done asynchronously and too late to be
consistently present in the crash reports.
It seems that the flag was only present in case of a second freeze.
Set the flag synchronously before generating the crash report.

Bug: 1056178
Change-Id: Ia7958c61a01dd9ffa592f3ba6b86481b50e8c89d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2074220Reviewed-by: Justin Cohen <justincohen@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Commit-Queue: Olivier Robin <olivierrobin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#745478}

ios/chrome/browser/crash_report/breakpad_helper.h

@@ -74,6 +74,9 @@ void SetMemoryWarningInProgress(bool value);
 
 // Sets a key indicating that UI thread is frozen (if value is 'true'),
 // otherwise remove the key.
+// Setting the value is synchronous as it is expected to be set just before the
+// report generation.
+// Unsetting the value is asynchronous.
 void SetHangReport(bool value);
 
 // Sets a key indicating the current free memory amount in KB. 0 does not remove

ios/chrome/browser/crash_report/breakpad_helper.mm

@@ -279,7 +279,7 @@ void SetMemoryWarningInProgress(bool value) {
 
 void SetHangReport(bool value) {
   if (value)
-    AddReportParameter(kHangReport, @"yes", true);
+    AddReportParameter(kHangReport, @"yes", false);
   else
     RemoveReportParameter(kHangReport);
 }

ios/chrome/browser/crash_report/main_thread_freeze_detector.mm

@@ -166,12 +166,12 @@ void LogRecoveryTime(base::TimeDelta time) {
   }
   if ([[NSDate date] timeIntervalSinceDate:self.lastSeenMainThread] >
       self.delay) {
+    breakpad_helper::SetHangReport(true);
     [[BreakpadController sharedInstance]
         withBreakpadRef:^(BreakpadRef breakpadRef) {
           if (!breakpadRef) {
             return;
           }
-          breakpad_helper::SetHangReport(true);
           NSDictionary* breakpadReportInfo =
               BreakpadGenerateReport(breakpadRef, nil);
           if (!breakpadReportInfo) {
@@ -207,6 +207,7 @@ void LogRecoveryTime(base::TimeDelta time) {
               }
                  forKey:@(kNsUserDefaultKeyLastSessionInfo)];
           self.reportGenerated = YES;
+          breakpad_helper::SetHangReport(false);
         }];
     return;
   }