diff -r 000000000000 -r 6474c204b198 widget/cocoa/nsCocoaFeatures.mm
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/widget/cocoa/nsCocoaFeatures.mm	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,151 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#define MAC_OS_X_VERSION_MASK      0x0000FFFF
+#define MAC_OS_X_VERSION_10_6_HEX  0x00001060
+#define MAC_OS_X_VERSION_10_7_HEX  0x00001070
+#define MAC_OS_X_VERSION_10_8_HEX  0x00001080
+#define MAC_OS_X_VERSION_10_9_HEX  0x00001090
+#define MAC_OS_X_VERSION_10_10_HEX 0x000010A0
+
+// This API will not work for OS X 10.10, see Gestalt.h.
+
+#include "nsCocoaFeatures.h"
+#include "nsCocoaUtils.h"
+#include "nsDebug.h"
+#include "nsObjCExceptions.h"
+
+#import <Cocoa/Cocoa.h>
+
+int32_t nsCocoaFeatures::mOSXVersion = 0;
+int32_t nsCocoaFeatures::mOSXVersionMajor = 0;
+int32_t nsCocoaFeatures::mOSXVersionMinor = 0;
+int32_t nsCocoaFeatures::mOSXVersionBugFix = 0;
+
+static int intAtStringIndex(NSArray *array, int index)
+{
+    return [(NSString *)[array objectAtIndex:index] integerValue];
+}
+
+static void GetSystemVersion(int &major, int &minor, int &bugfix)
+{
+    major = minor = bugfix = 0;
+    
+    NSString* versionString = [[NSDictionary dictionaryWithContentsOfFile:
+                                @"/System/Library/CoreServices/SystemVersion.plist"] objectForKey:@"ProductVersion"];
+    NSArray* versions = [versionString componentsSeparatedByString:@"."];
+    NSUInteger count = [versions count];
+    if (count > 0) {
+        major = intAtStringIndex(versions, 0);
+        if (count > 1) {
+            minor = intAtStringIndex(versions, 1);
+            if (count > 2) {
+                bugfix = intAtStringIndex(versions, 2);
+            }
+        }
+    }
+}
+
+/*static*/ void
+nsCocoaFeatures::InitializeVersionNumbers()
+{
+    NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
+
+    // Provide an autorelease pool to avoid leaking Cocoa objects,
+    // as this gets called before the main autorelease pool is in place.
+    nsAutoreleasePool localPool;
+
+    int major, minor, bugfix;
+    GetSystemVersion(major, minor, bugfix);
+
+    mOSXVersionMajor = major;
+    mOSXVersionMinor = minor;
+    mOSXVersionBugFix = bugfix;
+
+    if (major < 10) {
+        NS_ERROR("Couldn't determine OS X version, assuming 10.6");
+        mOSXVersion = MAC_OS_X_VERSION_10_6_HEX;
+        mOSXVersionMajor = 10;
+        mOSXVersionMinor = 6;
+        mOSXVersionBugFix = 0;
+    } else if (minor < 6) {
+        NS_ERROR("OS X version too old, assuming 10.6");
+        mOSXVersion = MAC_OS_X_VERSION_10_6_HEX;
+        mOSXVersionMinor = 6;
+        mOSXVersionBugFix = 0;
+    } else {
+        mOSXVersion = 0x1000 + (minor << 4);
+    }
+
+    NS_OBJC_END_TRY_ABORT_BLOCK;
+}
+
+/* static */ int32_t
+nsCocoaFeatures::OSXVersion()
+{
+    if (!mOSXVersion) {
+        InitializeVersionNumbers();
+    }
+    return mOSXVersion;
+}
+
+/* static */ int32_t
+nsCocoaFeatures::OSXVersionMajor()
+{
+    if (!mOSXVersion) {
+        InitializeVersionNumbers();
+    }
+    return mOSXVersionMajor;
+}
+
+/* static */ int32_t
+nsCocoaFeatures::OSXVersionMinor()
+{
+    if (!mOSXVersion) {
+        InitializeVersionNumbers();
+    }
+    return mOSXVersionMinor;
+}
+
+/* static */ int32_t
+nsCocoaFeatures::OSXVersionBugFix()
+{
+    if (!mOSXVersion) {
+        InitializeVersionNumbers();
+    }
+    return mOSXVersionBugFix;
+}
+
+/* static */ bool
+nsCocoaFeatures::SupportCoreAnimationPlugins()
+{
+    // Disallow Core Animation on 10.5 because of crashes.
+    // See Bug 711564.
+    return (OSXVersion() >= MAC_OS_X_VERSION_10_6_HEX);
+}
+
+/* static */ bool
+nsCocoaFeatures::OnLionOrLater()
+{
+    return (OSXVersion() >= MAC_OS_X_VERSION_10_7_HEX);
+}
+
+/* static */ bool
+nsCocoaFeatures::OnMountainLionOrLater()
+{
+    return (OSXVersion() >= MAC_OS_X_VERSION_10_8_HEX);
+}
+
+/* static */ bool
+nsCocoaFeatures::OnMavericksOrLater()
+{
+    return (OSXVersion() >= MAC_OS_X_VERSION_10_9_HEX);
+}
+
+/* static */ bool
+nsCocoaFeatures::OnYosemiteOrLater()
+{
+    return (OSXVersion() >= MAC_OS_X_VERSION_10_10_HEX);
+}