Enable parallel compiles. This speeds up builds on 4-processor system…

…s by about 30%, and at least doesn't hurt 2-processor systems.

Review URL: http://codereview.chromium.org/16521

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@7573 0039d316-1c4b-4281-b951-d872f2087c98

build/internal/essential.vsprops

@@ -9,6 +9,7 @@
 	>
 	<Tool
 		Name="VCCLCompilerTool"
+		AdditionalOptions="/MP"
 		AdditionalIncludeDirectories="$(SolutionDir)..;$(SDKIncludes)"
 		PreprocessorDefinitions="_WIN32_WINNT=0x0600;WINVER=0x0600;WIN32;_WINDOWS;_HAS_EXCEPTIONS=0;NOMINMAX;_CRT_RAND_S;CERT_CHAIN_PARA_HAS_EXTRA_FIELDS;WIN32_LEAN_AND_MEAN;_SECURE_ATL;_HAS_TR1=0"
 		MinimalRebuild="false"