Populate stack frames with unloaded module info.

This CL hits lots of source files because:
 1. An update to the CodeModule virtual class. I added an is_loaded
  method to specify whether the module is loaded. There were several
  mocks/test classes that needed to be updated with an implementation.
  An alternative to this route would be to modify
  MinidumpUnloadedModule::code_file to prepend "Unloaded_" to the
  module name.

 2. Added an unloaded_modules parameter to
  StackFrameSymbolizer::FillSourceLineInfo.

BUG=

Change-Id: Ic9c7f7c7b7e932a154a5d4ccf292c1527d8da09f
Reviewed-on: https://chromium-review.googlesource.com/430241
Reviewed-by: Ivan Penkov <ivanpe@chromium.org>

src/google_breakpad/processor/code_module.h

@@ -94,6 +94,9 @@ class CodeModule {
   // should always reflect the original values (reported in the minidump).
   virtual uint64_t shrink_down_delta() const = 0;
   virtual void SetShrinkDownDelta(uint64_t shrink_down_delta) = 0;
+
+  // Whether the module was unloaded from memory.
+  virtual bool is_unloaded() const = 0;
 };
 
 }  // namespace google_breakpad