Revert of Omnibox: Combine Two Input Type Enums into One

components/metrics/proto/omnibox_event.proto

Index: components/metrics/proto/omnibox_event.proto
diff --git a/components/metrics/proto/omnibox_event.proto b/components/metrics/proto/omnibox_event.proto
index afef1a0be98cb5cf93435f4f22cb24c48f07ae65..33079549d38dd7ff58032f155a4b59fb2b515b6e 100644
--- a/components/metrics/proto/omnibox_event.proto
+++ b/components/metrics/proto/omnibox_event.proto
@@ -9,8 +9,6 @@
 option optimize_for = LITE_RUNTIME;
 
 package metrics;
-
-import "omnibox_input_type.proto";
 
 // Next tag: 17
 message OmniboxEventProto {
@@ -132,7 +130,18 @@
   }
   optional PageClassification current_page_classification = 10;
 
-  optional OmniboxInputType.Type input_type = 8;
+  // What kind of input the user provided.
+  enum InputType {
+    INVALID = 0;        // Empty input (should not reach here)
+    UNKNOWN = 1;        // Valid input whose type cannot be determined
+    REQUESTED_URL = 2;  // DEPRECATED. Input autodetected as UNKNOWN, which the
+                        // user wants to treat as an URL by specifying a
+                        // desired_tld
+    URL = 3;            // Input autodetected as a URL
+    QUERY = 4;          // Input autodetected as a query
+    FORCED_QUERY = 5;   // Input forced to be a query by an initial '?'
+  }
+  optional InputType input_type = 8;
 
   // An enum used in multiple places below.
   enum ProviderType {