CL for perf tryjob on android

content/child/blink_platform_impl.cc

Index: content/child/blink_platform_impl.cc
diff --git a/content/child/blink_platform_impl.cc b/content/child/blink_platform_impl.cc
index 7d1cb401618b34d3d34bad8be278cc70b15b23fe..12642be096f358eb8c64b2cbc93237ece088afec 100644
--- a/content/child/blink_platform_impl.cc
+++ b/content/child/blink_platform_impl.cc
@@ -586,29 +586,53 @@ void BlinkPlatformImpl::decrementStatsCounter(const char* name) {
 void BlinkPlatformImpl::incrementStatsCounter(const char* name) {
 }
 
-void BlinkPlatformImpl::histogramCustomCounts(
-    const char* name, int sample, int min, int max, int bucket_count) {
+void BlinkPlatformImpl::histogramCustomCounts(const char* name,
+                                              int sample,
+                                              int min,
+                                              int max,
+                                              int bucket_count,
+                                              HistogramCacheSlot* cache_slot) {
   // Copied from histogram macro, but without the static variable caching
   // the histogram because name is dynamic.
-  base::HistogramBase* counter =
-      base::Histogram::FactoryGet(name, min, max, bucket_count,
-          base::HistogramBase::kUmaTargetedHistogramFlag);
+  base::HistogramBase* counter = 0;
+  if (cache_slot)
+    counter = reinterpret_cast<base::HistogramBase*>(*cache_slot);
+
+  if (!counter) {
+    counter = base::Histogram::FactoryGet(
+        name, min, max, bucket_count,
+        base::HistogramBase::kUmaTargetedHistogramFlag);
+  }
   DCHECK_EQ(name, counter->histogram_name());
   counter->Add(sample);
+  if (cache_slot)
+    *cache_slot = counter;
 }
 
-void BlinkPlatformImpl::histogramEnumeration(
-    const char* name, int sample, int boundary_value) {
+void BlinkPlatformImpl::histogramEnumeration(const char* name,
+                                             int sample,
+                                             int boundary_value,
+                                             HistogramCacheSlot* cache_slot) {
   // Copied from histogram macro, but without the static variable caching
   // the histogram because name is dynamic.
-  base::HistogramBase* counter =
-      base::LinearHistogram::FactoryGet(name, 1, boundary_value,
-          boundary_value + 1, base::HistogramBase::kUmaTargetedHistogramFlag);
+  base::HistogramBase* counter = 0;
+  if (cache_slot)
+    counter = reinterpret_cast<base::HistogramBase*>(*cache_slot);
+
+  if (!counter) {
+    counter = base::LinearHistogram::FactoryGet(
+        name, 1, boundary_value, boundary_value + 1,
+        base::HistogramBase::kUmaTargetedHistogramFlag);
+  }
   DCHECK_EQ(name, counter->histogram_name());
   counter->Add(sample);
+  if (cache_slot)
+    *cache_slot = counter;
 }
 
-void BlinkPlatformImpl::histogramSparse(const char* name, int sample) {
+void BlinkPlatformImpl::histogramSparse(const char* name,
+                                        int sample,
+                                        HistogramCacheSlot* cache_slot) {
   // For sparse histograms, we can use the macro, as it does not incorporate a
   // static.
   UMA_HISTOGRAM_SPARSE_SLOWLY(name, sample);