Provide access to process private and shared memory size from WebKit code

webkit/glue/webkitplatformsupport_impl.cc

Index: webkit/glue/webkitplatformsupport_impl.cc
diff --git a/webkit/glue/webkitplatformsupport_impl.cc b/webkit/glue/webkitplatformsupport_impl.cc
index 6003cce1c4ffea8838b2c85130904d4213f15281..062f91651ed917552eab8e51e0c14cb19e994de7 100644
--- a/webkit/glue/webkitplatformsupport_impl.cc
+++ b/webkit/glue/webkitplatformsupport_impl.cc
@@ -669,6 +669,22 @@ WebKit::WebString WebKitPlatformSupportImpl::signedPublicKeyAndChallengeString(
   return WebKit::WebString("");
 }
 
+static base::ProcessMetrics* CurrentProcessMetrics() {
+  using base::ProcessMetrics;
+#if defined(OS_MACOSX)
+  static ProcessMetrics* process_metrics =
+      // The default port provider is sufficient to get data for the current
+      // process.
+      ProcessMetrics::CreateProcessMetrics(base::GetCurrentProcessHandle(),
+                                           NULL);
+#else
+  static ProcessMetrics* process_metrics =
+      ProcessMetrics::CreateProcessMetrics(base::GetCurrentProcessHandle());
+#endif
+  DCHECK(process_metrics);
+  return process_metrics;
+}
+
 #if defined(OS_LINUX) || defined(OS_ANDROID)
 static size_t memoryUsageMB() {
   struct mallinfo minfo = mallinfo();
@@ -684,24 +700,9 @@ static size_t memoryUsageMB() {
   v8::V8::GetHeapStatistics(&stat);
   return mem_usage + (static_cast<uint64_t>(stat.total_heap_size()) >> 20);
 }
-#elif defined(OS_MACOSX)
-static size_t memoryUsageMB() {
-  using base::ProcessMetrics;
-  static ProcessMetrics* process_metrics =
-      // The default port provider is sufficient to get data for the current
-      // process.
-      ProcessMetrics::CreateProcessMetrics(base::GetCurrentProcessHandle(),
-                                           NULL);
-  DCHECK(process_metrics);
-  return process_metrics->GetWorkingSetSize() >> 20;

[ulan, 2012/09/21 13:30:08]

Just noticed that this is missing in the current ToT.

Was this removed intentionally? 

GetPagefileUsage() returns virtual memory size and therefore greatly
overestimates real memory usage. This causes WebKit to send bogus low memory
notifications to V8 and leads to big GC pauses. It is better to use
GetWorkingSetSize(). 

[yurys, 2012/09/21 13:52:12]

Looks like GetWorkingSetSize was deleted by mistake when I extracted
CurrentProcessMetrics function. We should return it back.

-}
 #else
 static size_t memoryUsageMB() {
-  using base::ProcessMetrics;
-  static ProcessMetrics* process_metrics =
-      ProcessMetrics::CreateProcessMetrics(base::GetCurrentProcessHandle());
-  DCHECK(process_metrics);
-  return process_metrics->GetPagefileUsage() >> 20;
+  return CurrentProcessMetrics()->GetPagefileUsage() >> 20;
 }
 #endif
 
@@ -748,6 +749,12 @@ size_t WebKitPlatformSupportImpl::highUsageDeltaMB() {
 }
 #endif
 
+bool WebKitPlatformSupportImpl::processMemorySizesInBytes(
+    size_t* private_bytes,
+    size_t* shared_bytes) {
+  return CurrentProcessMetrics()->GetMemoryBytes(private_bytes, shared_bytes);
+}
+
 void WebKitPlatformSupportImpl::SuspendSharedTimer() {
   ++shared_timer_suspended_;
 }