Doxygenize the documentation comments

There were many // comment used to document classes, functions etc. but
those are not picked up by doxygen which expects /// comments. This
converts many comments from // to /// in order to improve the generated
documentation.

BUG=
R=jvoung@chromium.org, kschimpf@google.com

Review URL: https://codereview.chromium.org/1216963007.
diff --git a/src/IceCompileServer.h b/src/IceCompileServer.h
index b5093df..e027cbb 100644
--- a/src/IceCompileServer.h
+++ b/src/IceCompileServer.h
@@ -6,10 +6,11 @@
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
-//
-// This file declares the compile server. Given a compiler implementation,
-// it dispatches compile requests to the implementation.
-//
+///
+/// \file
+/// This file declares the compile server. Given a compiler implementation,
+/// it dispatches compile requests to the implementation.
+///
 //===----------------------------------------------------------------------===//
 
 #ifndef SUBZERO_SRC_ICECOMPILESERVER_H
@@ -26,17 +27,17 @@
 
 namespace Ice {
 
-// A CompileServer awaits compile requests, and dispatches the requests
-// to a given Compiler. Each request is paired with an input stream,
-// a context (which has the output stream), and a set of arguments.
-// The CompileServer takes over the current thread to listen to requests,
-// and compile requests are handled on separate threads.
-//
-// Currently, this only handles a single request.
-//
-// When run on the commandline, it receives and therefore dispatches
-// the request immediately.  When run in the browser, it blocks waiting
-// for a request.
+/// A CompileServer awaits compile requests, and dispatches the requests
+/// to a given Compiler. Each request is paired with an input stream,
+/// a context (which has the output stream), and a set of arguments.
+/// The CompileServer takes over the current thread to listen to requests,
+/// and compile requests are handled on separate threads.
+///
+/// Currently, this only handles a single request.
+///
+/// When run on the commandline, it receives and therefore dispatches
+/// the request immediately.  When run in the browser, it blocks waiting
+/// for a request.
 class CompileServer {
   CompileServer() = delete;
   CompileServer(const CompileServer &) = delete;
@@ -59,7 +60,7 @@
   ErrorCode LastError;
 };
 
-// Commandline variant of the compile server.
+/// Commandline variant of the compile server.
 class CLCompileServer : public CompileServer {
   CLCompileServer() = delete;
   CLCompileServer(const CLCompileServer &) = delete;