Reverting 7573.

Doing a full build seems always fine. The issue is for incremental builds, it corrupts the PDBs. Errors look like:

glue.lib(autofill_form.obj) : fatal error LNK1318: Unexpected PDB error; RPC (23) '(0x000006BA)'
...\xmemory(155) : error C2471: cannot update program database '...\debug\obj\plugin_tests\vc80.pdb'

We'll probably need to upgrade to VS2008 to add it back.
Review URL: http://codereview.chromium.org/17208

git-svn-id: http://src.chromium.org/svn/trunk/src/build@7603 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

internal/essential.vsprops

@@ -9,7 +9,6 @@
 	>
 	<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"