StatisticsRecorder::SetCallback signature changed.

Chromium change:

https://source.chromium.org/chromium/chromium/src/+/b63857b27c74a69b28575c514bac9f5a237caaf1

commit b63857b27c74a69b28575c514bac9f5a237caaf1
Author: nuwanda <nuwanda@google.com>
Date:   Tue Aug 25 22:48:51 2020 +0000

    Add support for logging UMA histogram samples from trace config

    Now when histogram_samples category is set only the histograms listed
    in a trace config will be monitored. If there are no histograms in a
    trace config, the effect of enabling the histogram_samples category will
    remain the same: all the histograms will be monitored.

    Monitoring all the histograms results in a significant increase in
    trace size and processing time, that's why we need a way to monitor
    only a subset of histograms.

    Based on the events added to trace when enabling the histogram_samples
    category TBMv3 UMA metrics will be implemented.

    Bug: 1119834

components/p3a/brave_histogram_rewrite.cc

@@ -24,9 +24,11 @@ constexpr const char* kBravezationHistograms[] = {
 
 // TODO(iefremov): Replace a bunch of 'if's with something more elegant.
 // Records the given sample using the proper Brave way.
-void DoHistogramBravezation(base::StringPiece histogram_name,
+void DoHistogramBravezation(const char* histogram_name,
+                            uint64_t name_hash,
                             base::HistogramBase::Sample sample) {
-  if ("Bookmarks.Count.OnProfileLoad" == histogram_name) {
+  DCHECK(histogram_name);
+  if (strcmp("Bookmarks.Count.OnProfileLoad", histogram_name) == 0) {
     constexpr int kIntervals[] = {5, 20, 100, 500, 1000, 5000, 10000};
     const int* it =
         std::lower_bound(kIntervals, std::end(kIntervals), sample);
@@ -36,7 +38,7 @@ void DoHistogramBravezation(base::StringPiece histogram_name,
     return;
   }
 
-  if ("DefaultBrowser.State" == histogram_name) {
+  if (strcmp("DefaultBrowser.State", histogram_name) == 0) {
     int answer = 0;
     switch (sample) {
       case 0:  // Not default.
@@ -55,7 +57,7 @@ void DoHistogramBravezation(base::StringPiece histogram_name,
     UMA_HISTOGRAM_BOOLEAN("Brave.Core.IsDefault", answer);
   }
 
-  if ("Extensions.LoadExtension" == histogram_name) {
+  if (strcmp("Extensions.LoadExtension", histogram_name) == 0) {
     int answer = 0;
     if (sample == 1)
       answer = 1;
@@ -68,7 +70,7 @@ void DoHistogramBravezation(base::StringPiece histogram_name,
     return;
   }
 
-  if ("Tabs.TabCount" == histogram_name) {
+  if (strcmp("Tabs.TabCount", histogram_name) == 0) {
     int answer = 0;
     if (0 <= sample && sample <= 1) {
       answer = 0;
@@ -86,7 +88,7 @@ void DoHistogramBravezation(base::StringPiece histogram_name,
     return;
   }
 
-  if ("Tabs.WindowCount" == histogram_name) {
+  if (strcmp("Tabs.WindowCount", histogram_name) == 0) {
     int answer = 0;
     if (sample <= 0) {
       answer = 0;
@@ -109,7 +111,7 @@ void SetupHistogramsBraveization() {
   for (const char* histogram_name : kBravezationHistograms) {
     base::StatisticsRecorder::SetCallback(
         histogram_name,
-        base::BindRepeating(&DoHistogramBravezation, histogram_name));
+        base::BindRepeating(&DoHistogramBravezation));
   }
 }
 

components/p3a/brave_p3a_service.cc

@@ -199,8 +199,7 @@ void BraveP3AService::InitCallbacks() {
   for (const char* histogram_name : kCollectedHistograms) {
     base::StatisticsRecorder::SetCallback(
         histogram_name,
-        base::BindRepeating(&BraveP3AService::OnHistogramChanged, this,
-                            histogram_name));
+        base::BindRepeating(&BraveP3AService::OnHistogramChanged, this));
   }
 }
 
@@ -380,7 +379,8 @@ void BraveP3AService::StartScheduledUpload() {
   }
 }
 
-void BraveP3AService::OnHistogramChanged(base::StringPiece histogram_name,
+void BraveP3AService::OnHistogramChanged(const char* histogram_name,
+                                         uint64_t name_hash,
                                          base::HistogramBase::Sample sample) {
   std::unique_ptr<base::HistogramSamples> samples =
       base::StatisticsRecorder::FindHistogram(histogram_name)->SnapshotDelta();
@@ -392,7 +392,7 @@ void BraveP3AService::OnHistogramChanged(base::StringPiece histogram_name,
     base::PostTask(FROM_HERE, {content::BrowserThread::UI},
                    base::BindOnce(&BraveP3AService::OnHistogramChangedOnUI,
                                   this,
-                                  histogram_name,
+                                  base::StringPiece(histogram_name),
                                   kSuspendedMetricValue,
                                   kSuspendedMetricBucket));
     return;

components/p3a/brave_p3a_service.h

@@ -66,7 +66,8 @@ class BraveP3AService : public base::RefCountedThreadSafe<BraveP3AService>,
 
   // Invoked by callbacks registered by our service. Since these callbacks
   // can fire on any thread, this method reposts everything to UI thread.
-  void OnHistogramChanged(base::StringPiece histogram_name,
+  void OnHistogramChanged(const char* histogram_name,
+                          uint64_t name_hash,
                           base::HistogramBase::Sample sample);
 
   void OnHistogramChangedOnUI(base::StringPiece histogram_name,