Detect corrupt symbol files during minidump processing. Recover from the errors and use the good data if possible.

More specifically:
 - Detect corrupt symbols during minidump processing and provide the list of modules with corrupt symbols in the ProcessState.  This will allow listing the corrupt symbol files in the final crash report.
 - Skip and recover from symbol data parse errors - don't give up until 100 parse errors are seen.
 - In order to recover from '\0' (null terminator) in the middle of a symbol file, a couple of methods have to be updated to require both buffer pointer and length.  Previously they required only a buffer pointer (char *) and the size of the buffer was evaluated using strlen which is not reliable when the data is corrupt.  Most of the changes are due to these signature updates.
 - Added and updated unittests.

Also, updated minidump_stackwalk to show a WARNING for corrupt symbols.  Output looks like this:
...
Loaded modules:
0x000da000 - 0x000dafff  Google Chrome Canary  ???  (main)
0x000e0000 - 0x0417dfff  Google Chrome Framework  0.1500.0.3  (WARNING: Corrupt symbols, Google Chrome Framework, 4682A6B4136436C4BFECEB62D498020E0)
0x044a8000 - 0x04571fff  IOBluetooth  0.1.0.0
...
Review URL: https://breakpad.appspot.com/613002

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1200 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/google_breakpad/processor/source_line_resolver_interface.h

@@ -64,12 +64,15 @@ class SourceLineResolverInterface {
   virtual bool LoadModuleUsingMapBuffer(const CodeModule *module,
                                         const string &map_buffer) = 0;
 
-  // Add an interface to load symbol using C-String data insteading string.
+  // Add an interface to load symbol using C-String data instead of string.
   // This is useful in the optimization design for avoiding unnecessary copying
   // of symbol data, in order to improve memory efficiency.
   // LoadModuleUsingMemoryBuffer() does NOT take ownership of memory_buffer.
+  // LoadModuleUsingMemoryBuffer() null terminates the passed in buffer, if
+  // the last character is not a null terminator.
   virtual bool LoadModuleUsingMemoryBuffer(const CodeModule *module,
-                                           char *memory_buffer) = 0;
+                                           char *memory_buffer,
+                                           size_t memory_buffer_size) = 0;
 
   // Return true if the memory buffer should be deleted immediately after
   // LoadModuleUsingMemoryBuffer(). Return false if the memory buffer has to be
@@ -83,6 +86,9 @@ class SourceLineResolverInterface {
   // Returns true if the module has been loaded.
   virtual bool HasModule(const CodeModule *module) = 0;
 
+  // Returns true if the module has been loaded and it is corrupt.
+  virtual bool IsModuleCorrupt(const CodeModule *module) = 0;
+
   // Fills in the function_base, function_name, source_file_name,
   // and source_line fields of the StackFrame.  The instruction and
   // module_name fields must already be filled in.