Move duplicate CappedSizeInKB() to header file for sharing

Some jumbo builds broke because of too many CappedSizeInKB so moving
it to heap.h to unbreak the builds. It's a small inlined method.
The moved function is not using std::min to avoid including
<algorithm> in heap.h and potentially causing a measurable
build time regression.

TBR=mlippautz@chromium.org,haraken@chromium.org

Bug: 840789
Change-Id: I4e4bf3989235c6e7274a56f5c10823d8bb37a4df
Reviewed-on: https://chromium-review.googlesource.com/1090839Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Daniel Bratell <bratell@opera.com>
Commit-Queue: Daniel Bratell <bratell@opera.com>
Cr-Commit-Position: refs/heads/master@{#565289}

third_party/blink/renderer/platform/heap/heap.cc

@@ -352,15 +352,6 @@ void ThreadHeap::ReportMemoryUsageHistogram() {
   }
 }
 
-namespace {
-
-size_t CappedSizeInKB(size_t size) {
-  return std::min(size / 1024,
-                  static_cast<size_t>(std::numeric_limits<int>::max()));
-}
-
-}  // namespace
-
 void ThreadHeap::ReportMemoryUsageForTracing() {
   bool gc_tracing_enabled;
   TRACE_EVENT_CATEGORY_GROUP_ENABLED(TRACE_DISABLED_BY_DEFAULT("blink_gc"),

third_party/blink/renderer/platform/heap/heap.h

@@ -31,6 +31,7 @@
 #ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_HEAP_HEAP_H_
 #define THIRD_PARTY_BLINK_RENDERER_PLATFORM_HEAP_HEAP_H_
 
+#include <limits>
 #include <memory>
 
 #include "base/macros.h"
@@ -601,6 +602,15 @@ inline bool ThreadHeap::IsNormalArenaIndex(int index) {
          index <= BlinkGC::kNormalPage4ArenaIndex;
 }
 
+// Helper function to convert a byte count to a KB count, capping at
+// INT_MAX if the number is larger than that. Useful for reporting
+// purposes.
+constexpr size_t CappedSizeInKB(size_t size) {
+  size_t size_kb = size / 1024;
+  size_t limit = std::numeric_limits<int>::max();
+  return size_kb > limit ? limit : size_kb;
+}
+
 #define DECLARE_EAGER_FINALIZATION_OPERATOR_NEW() \
  public:                                          \
   GC_PLUGIN_IGNORE("491488")                      \

third_party/blink/renderer/platform/heap/thread_state.cc

@@ -409,7 +409,7 @@ double ThreadState::HeapGrowingRate() {
       estimated_size > 0 ? 1.0 * current_size / estimated_size : 100;
   TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("blink_gc"),
                  "ThreadState::heapEstimatedSizeKB",
-                 std::min(estimated_size / 1024, static_cast<size_t>(INT_MAX)));
+                 CappedSizeInKB(estimated_size));
   TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("blink_gc"),
                  "ThreadState::heapGrowingRate",
                  static_cast<int>(100 * growing_rate));
@@ -426,7 +426,7 @@ double ThreadState::PartitionAllocGrowingRate() {
       estimated_size > 0 ? 1.0 * current_size / estimated_size : 100;
   TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("blink_gc"),
                  "ThreadState::partitionAllocEstimatedSizeKB",
-                 std::min(estimated_size / 1024, static_cast<size_t>(INT_MAX)));
+                 CappedSizeInKB(estimated_size));
   TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("blink_gc"),
                  "ThreadState::partitionAllocGrowingRate",
                  static_cast<int>(100 * growing_rate));
@@ -1002,11 +1002,6 @@ BlinkGCObserver::~BlinkGCObserver() {
 
 namespace {
 
-size_t CappedSizeInKB(size_t size) {
-  return std::min(size / 1024,
-                  static_cast<size_t>(std::numeric_limits<int>::max()));
-}
-
 void UpdateHistogramsAndCounters(const ThreadHeapStatsCollector::Event& event) {
   DEFINE_STATIC_LOCAL(EnumerationHistogram, gc_reason_histogram,
                       ("BlinkGC.GCReason", BlinkGC::kLastGCReason + 1));