Add net::SdchSourceStream and net::SdchPolicyDelegate

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 3147674ab9609b11dbc6d65540db2d4e1acb93ec..ff8678d5e0dae690a4fda6171a1fbe705254a725 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -28987,6 +28987,13 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Net.ContentDecodingFailed2.FilterType" enum="NetFilterType2">
+  <owner>xunjieli@chromium.org</owner>
+  <summary>
+    For each CONTENT_DECODING_FAILED, record the filter that failed.
+  </summary>
+</histogram>
+
 <histogram name="net.CookieBackingStoreUpdateResults"
     enum="BackingStoreResults">
   <obsolete>
@@ -92097,6 +92104,21 @@ value.
   <int value="6" label="Unsupported"/>
 </enum>
 
+<enum name="NetFilterType2" type="int">
+  <summary>
+    Specific content decoding filter.  See net::SourceStream::SourceType for
+    more details
+  </summary>
+  <int value="0" label="Brotli"/>
+  <int value="1" label="Deflate"/>
+  <int value="2" label="GZIP"/>
+  <int value="3" label="GZIPFallback"/>
+  <int value="4" label="SDCH"/>
+  <int value="5" label="SDCHPossible"/>
+  <int value="6" label="Invalid"/>
+  <int value="7" label="None"/>
+</enum>
+
 <enum name="NetInternalsUiFeature" type="int">
   <int value="0" label="NetInternals"/>
   <int value="1" label="Connection tester"/>