ipp_converter: Use push_back where appropriate

- Use push_back instead of emplace_back where appropriate
- See abseil.io/tips/112

Bug: None
Test: manual
Change-Id: I10538be7fd33b4a66da7409f54ac526b18ee6479
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2283765
Auto-Submit: Zentaro Kavanagh <zentaro@chromium.org>
Reviewed-by: Sean Kau <skau@chromium.org>
Commit-Queue: Zentaro Kavanagh <zentaro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#785948}

chrome/services/ipp_parser/public/cpp/ipp_converter.cc

@@ -119,8 +119,7 @@ std::vector<bool> IppGetBools(ipp_attribute_t* attr) {
   std::vector<bool> ret;
   for (int i = 0; i < ippGetCount(attr); ++i) {
     // No decipherable failure condition for this libCUPS method.
-    bool v = ippGetBoolean(attr, i);
-    ret.emplace_back(v);
+    ret.push_back(ippGetBoolean(attr, i));
   }
   return ret;
 }
@@ -132,7 +131,7 @@ base::Optional<std::vector<int>> IppGetInts(ipp_attribute_t* attr) {
     if (!v) {
       return base::nullopt;
     }
-    ret.emplace_back(v);
+    ret.push_back(v);
   }
   return ret;
 }
@@ -390,7 +389,7 @@ ipp_parser::mojom::IppMessagePtr ConvertIppToMojo(ipp_t* ipp) {
         NOTREACHED();
     }
 
-    attributes.emplace_back(std::move(attrptr));
+    attributes.push_back(std::move(attrptr));
   }
 
   ret->attributes = std::move(attributes);