Fix to cache NOT_FOUND results from symbol supplier on a per-minidump basis

http://breakpad.appspot.com/64001

R=ted.mielczarek, brdevmn
A=nealsid



git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@543 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/processor/stackwalker.cc

@@ -93,6 +93,8 @@ bool Stackwalker::Walk(CallStack *stack) {
         frame->module = module;
         if (resolver_ &&
             !resolver_->HasModule(frame->module->code_file()) &&
+            no_symbol_modules_.find(
+                module->code_file()) == no_symbol_modules_.end() &&
             supplier_) {
           string symbol_data, symbol_file;
           SymbolSupplier::SymbolResult symbol_result =
@@ -105,6 +107,7 @@ bool Stackwalker::Walk(CallStack *stack) {
                                                   symbol_data);
               break;
             case SymbolSupplier::NOT_FOUND:
+              no_symbol_modules_.insert(module->code_file());
               break;  // nothing to do
             case SymbolSupplier::INTERRUPT:
               return false;