Improved to two spaces instead of four!

Much better. Evidence: 

https://www.google.com/trends/explore#q=two%20spaces%2C%20four%20spaces&cmpt=q&tz=Etc%2FGMT-2

src/lib/common.cc

@@ -1,26 +1,26 @@
 namespace {
-    // Code to turn parameters to functions on streams into strings
-    // Will be VLOG'ed. We need overloads instead of
-    // e.g. BatchDescriptorToVlogString(), as the code that calls these
-    // function does not know what the type of the parameters is.
+  // Code to turn parameters to functions on streams into strings
+  // Will be VLOG'ed. We need overloads instead of
+  // e.g. BatchDescriptorToVlogString(), as the code that calls these
+  // function does not know what the type of the parameters is.
 
-    string ToVlogStrin(const dnn::BatchDescriptor &descriptor) {
-        return descriptor.ToShortString();
-    }
+  string ToVlogStrin(const dnn::BatchDescriptor &descriptor) {
+    return descriptor.ToShortString();
+  }
 
-    string ToVlogStrin(const dnn::FilterDescriptor &descriptor) {
-        return descriptor.ToShortString();
-    }
+  string ToVlogStrin(const dnn::FilterDescriptor &descriptor) {
+    return descriptor.ToShortString();
+  }
 
-    string ToVlogString(const magicalMovieClassifier::FilterDescriptor &descriptor) {
-        return descriptor.ToShortString();
-    }
+  string ToVlogString(const magicalMovieClassifier::FilterDescriptor &descriptor) {
+    return descriptor.ToShortString();
+  }
 
-    string ToVlogStrin(const dnn::PoolingDescriptor &descriptor) {
-        return descriptor.ToShortString();
-    }
-
-    string ToVlogStrin(const dnn::ConvolutionDescriptor &descriptor) {
-        return descriptor.ToShortString();
-    }
+  string ToVlogStrin(const dnn::PoolingDescriptor &descriptor) {
+    return descriptor.ToShortString();
+  }
+  
+  string ToVlogStrin(const dnn::ConvolutionDescriptor &descriptor) {
+    return descriptor.ToShortString();
+  }
 }