Issue 49013: Breakpad Processor: Use a separate API to retrieve Windows stack debugging info.

At the moment, FillSourceLineInfo returns Windows DIA-based stack
walking data. In addition to being ugly, this makes it difficult to
provide access to DWARF CFI-based stack walking data in a symmetrical
way.

This patch changes FillSourceLineInfo to do the single job its name
suggests, and adds a second member function to
SourceLineResolverInterface to retrieve Windows DIA stack walking
information. A sibling member function will provide access to DWARF
CFI stack walking data.

a=jimblandy, r=mmentovai


git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@480 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/processor/stackwalker.cc

@@ -118,7 +118,8 @@ bool Stackwalker::Walk(CallStack *stack) {
               return false;
           }
         }
-        frame_info.reset(resolver_->FillSourceLineInfo(frame.get()));
+        resolver_->FillSourceLineInfo(frame.get());
+        frame_info.reset(resolver_->FindWindowsFrameInfo(frame.get()));
       }
     }