Revert of Upgrade Blink to milliseconds-based last modified filetimes, part 3.

Source/platform/FileMetadata.h

Index: Source/platform/FileMetadata.h
diff --git a/Source/platform/FileMetadata.h b/Source/platform/FileMetadata.h
index 36e549c08528d278690be7ec3907abf2e48f1005..924082dcb7e31dc8feb025293ea161f323ec9897 100644
--- a/Source/platform/FileMetadata.h
+++ b/Source/platform/FileMetadata.h
@@ -42,18 +42,10 @@
 inline double invalidFileTime() { return std::numeric_limits<double>::quiet_NaN(); }
 inline bool isValidFileTime(double time) { return std::isfinite(time); }
 
-class FileMetadata {
-public:
-    FileMetadata()
-        : modificationTimeMS(invalidFileTime())
-        , length(-1)
-        , type(TypeUnknown)
-    {
-    }
-
-    // The last modification time of the file, in milliseconds.
-    // The value NaN means that the time is not known.
-    double modificationTimeMS;
+struct FileMetadata {
+    // The last modification time of the file, in seconds.
+    // The value 0.0 means that the time is not set.
+    double modificationTime;
 
     // The length of the file in bytes.
     // The value -1 means that the length is not set.
@@ -67,6 +59,8 @@
 
     Type type;
     String platformPath;
+
+    FileMetadata() : modificationTime(invalidFileTime()), length(-1), type(TypeUnknown) { }
 };
 
 PLATFORM_EXPORT bool getFileSize(const String&, long long& result);