Let breakpad build with -Wall on OS X and Linux.

A=thakis@chromium.org
Original Review: https://codereview.chromium.org/1550933002/

R=thakis@chromium.org

Review URL: https://codereview.chromium.org/1554613002 .

src/common/linux/dump_symbols.cc

@@ -889,7 +889,6 @@ bool ReadSymbolDataElfClass(const typename ElfClass::Ehdr* elf_header,
                             const DumpOptions& options,
                             Module** out_module) {
   typedef typename ElfClass::Ehdr Ehdr;
-  typedef typename ElfClass::Shdr Shdr;
 
   *out_module = NULL;
 

src/common/linux/libcurl_wrapper.h

@@ -43,7 +43,7 @@ namespace google_breakpad {
 class LibcurlWrapper {
  public:
   LibcurlWrapper();
-  ~LibcurlWrapper();
+  virtual ~LibcurlWrapper();
   virtual bool Init();
   virtual bool SetProxy(const string& proxy_host,
                         const string& proxy_userpwd);

src/common/linux/synth_elf.cc

@@ -213,8 +213,10 @@ void ELF::Finish() {
 SymbolTable::SymbolTable(Endianness endianness,
                          size_t addr_size,
                          StringTable& table) : Section(endianness),
-                                               addr_size_(addr_size),
                                                table_(table) {
+#ifndef NDEBUG
+  addr_size_ = addr_size;
+#endif
   assert(addr_size_ == 4 || addr_size_ == 8);
 }
 

src/common/linux/synth_elf.h

@@ -173,7 +173,9 @@ class SymbolTable : public Section {
                  uint64_t size, unsigned info, uint16_t shndx);
 
  private:
+#ifndef NDEBUG
   size_t addr_size_;
+#endif
   StringTable& table_;
 };