Allow compiling the google-breakpad code using a global ::string class instead of std::string.

For more details take a look at common/using_std_string.h

BUG=

Change-Id: Ifebfc57f691ef3a3bef8cfed7106c567985edffc
Reviewed-on: https://chromium-review.googlesource.com/399738
Reviewed-by: Mark Mentovai <mark@chromium.org>

src/processor/stackwalker_unittest_utils.h

@@ -197,7 +197,7 @@ class MockSymbolSupplier: public google_breakpad::SymbolSupplier {
 
   // Copies the passed string contents into a newly allocated buffer.
   // The newly allocated buffer will be freed during destruction.
-  char* CopySymbolDataAndOwnTheCopy(const std::string &info,
+  char* CopySymbolDataAndOwnTheCopy(const string &info,
                                     size_t *symbol_data_size) {
     *symbol_data_size = info.size() + 1;
     char *symbol_data = new char[*symbol_data_size];

src/processor/symbolic_constants_win.cc

@@ -36,7 +36,6 @@
 #include <string>
 
 #include "common/stdio_wrapper.h"
-#include "common/using_std_string.h"
 #include "google_breakpad/common/breakpad_types.h"
 #include "google_breakpad/common/minidump_exception_win32.h"
 #include "processor/symbolic_constants_win.h"

src/processor/symbolic_constants_win.h

@@ -38,12 +38,13 @@
 
 #include <string>
 
+#include "common/using_std_string.h"
 #include "google_breakpad/common/breakpad_types.h"
 
 namespace google_breakpad {
 
 /* Converts a NTSTATUS code to a reason string. */
-std::string NTStatusToString(uint32_t ntstatus);
+string NTStatusToString(uint32_t ntstatus);
 
 }  // namespace google_breakpad