Add UMA to estimate deroppable memory usage of encoded data size in Resources

third_party/WebKit/Source/core/fetch/Resource.cpp

Index: third_party/WebKit/Source/core/fetch/Resource.cpp
diff --git a/third_party/WebKit/Source/core/fetch/Resource.cpp b/third_party/WebKit/Source/core/fetch/Resource.cpp
index 723beaef078e02bae7e48b631f91cd3c31c8ab38..977345cf05fdc46338c0ae82919f609f27a2c950 100644
--- a/third_party/WebKit/Source/core/fetch/Resource.cpp
+++ b/third_party/WebKit/Source/core/fetch/Resource.cpp
@@ -859,6 +859,15 @@ void Resource::onMemoryStateChange(MemoryState state) {
   m_cacheHandler->clearCachedMetadata(CachedMetadataHandler::CacheLocally);
 }
 
+bool Resource::isReloadable() const {
+  ResourceClientWalker<ResourceClient> w(m_finishedClients);
+  while (ResourceClient* c = w.next()) {
+    if (!c->isReloadable())
+      return false;
+  }
+  return true;
+}
+
 void Resource::onMemoryDump(WebMemoryDumpLevelOfDetail levelOfDetail,
                             WebProcessMemoryDump* memoryDump) const {
   static const size_t kMaxURLReportLength = 128;