Safebrowsing: change gethash caching to match api 2.3 rules, fix some corner cases.

chrome/browser/safe_browsing/safe_browsing_util.cc

Index: chrome/browser/safe_browsing/safe_browsing_util.cc
diff --git a/chrome/browser/safe_browsing/safe_browsing_util.cc b/chrome/browser/safe_browsing/safe_browsing_util.cc
index 40732d635d79d77538d8f3d7b8298af902c9355e..dfffeae8b5ad814bba65acc8fec68010099f5b7d 100644
--- a/chrome/browser/safe_browsing/safe_browsing_util.cc
+++ b/chrome/browser/safe_browsing/safe_browsing_util.cc
@@ -57,6 +57,16 @@ void SBChunkList::clear() {
   chunks_.clear();
 }
 
+// SBCachedFullHashResult ------------------------------------------------------
+
+SBCachedFullHashResult::SBCachedFullHashResult() {}
+
+SBCachedFullHashResult::SBCachedFullHashResult(
+    const base::Time& in_expire_after)
+    : expire_after(in_expire_after) {}
+
+SBCachedFullHashResult::~SBCachedFullHashResult() {}
+
 // SBListChunkRanges -----------------------------------------------------------
 
 SBListChunkRanges::SBListChunkRanges(const std::string& n) : name(n) {}