Add UMA metrics for Android Chrome Google Search.

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 c7a09481bd9ef7199dfb280a2f6ffdb80e03e432..cfe2df8a27bc8d467bd1cf4f58669634b9fe3a20 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -8180,6 +8180,35 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="GoogleSearch.AccessPoint" enum="SearchAccessPoint">
+  <owner>Please list the metric's owners. Add more owner tags as needed.</owner>
+  <summary>
+    Counts number of Google searches from various access points in the browser.
+  </summary>
+</histogram>
+
+<histogram name="GoogleSearch.AccessPoint_PrerenderDisabled"

[Alexei Svitkine (slow), 2014/06/20 16:27:35]

Nit: Please use the histogram_suffixes feature (see other examples in this file)
to define the suffixes on the existing histogram.

[kmadhusu, 2014/06/20 16:53:26]

Done.

+    enum="SearchAccessPoint">
+  <owner>kmadhusu@chromium.org</owner>
+  <summary>
+    Counts number of Google searches from various access points in the Android
+    Chrome browser when prerendering is disabled via &quot;Bandwidth
+    management&quot; settings or &quot;Privacy&quot; settings. Only recorded on
+    Android.
+  </summary>
+</histogram>
+
+<histogram name="GoogleSearch.AccessPoint_PrerenderEnabled"
+    enum="SearchAccessPoint">
+  <owner>kmadhusu@chromium.org</owner>
+  <summary>
+    Counts number of Google searches from various access points in the Android
+    Chrome browser when prerendering is enabled via &quot;Bandwidth
+    management&quot; settings and &quot;Privacy&quot; settings. Only recorded on
+    Android.
+  </summary>
+</histogram>
+
 <histogram name="GoogleUpdate.EffectivePolicy" enum="UpdatePolicy">
   <owner>gab@chromium.org</owner>
   <summary>
@@ -43621,6 +43650,19 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="3" label="SCT_STATUS_OK"/>
 </enum>
 
+<enum name="SearchAccessPoint" type="int">
+  <int value="0" label="Omnibox"/>
+  <int value="1" label="Omnibox Instant"/>
+  <int value="2" label="Direct Navigation"/>
+  <int value="3" label="Direct Navigation Instant"/>
+  <int value="4" label="Home Page"/>
+  <int value="5" label="Home Page Instant"/>
+  <int value="6" label="Search App"/>
+  <int value="7" label="Search App Instant"/>
+  <int value="8" label="Other"/>
+  <int value="9" label="Other Instant"/>
+</enum>
+
 <enum name="SearchEngine" type="int">
   <obsolete>
     Deprecated 8/2013. No longer generated.