Cleanup: Remove std::string("") usage and fix lint errors.

TBR=oshima@chromium.org,stevenjb@chromium.org,bajones@chromium.org,rch@chromium.org

Review URL: https://codereview.chromium.org/149573004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247844 0039d316-1c4b-4281-b951-d872f2087c98

ash/display/display_manager.cc

@@ -79,7 +79,7 @@ struct DisplayInfoSortFunctor {
 };
 
 struct ResolutionMatcher {
-  ResolutionMatcher(const gfx::Size& size) : size(size) {}
+  explicit ResolutionMatcher(const gfx::Size& size) : size(size) {}
   bool operator()(const Resolution& resolution) {
     return resolution.size == size;
   }
@@ -87,7 +87,7 @@ struct ResolutionMatcher {
 };
 
 struct ScaleComparator {
-  ScaleComparator(float s) : scale(s) {}
+  explicit ScaleComparator(float s) : scale(s) {}
 
   bool operator()(float s) const {
     const float kEpsilon = 0.0001f;
@@ -474,10 +474,8 @@ void DisplayManager::RegisterDisplayProperty(
     float ui_scale,
     const gfx::Insets* overscan_insets,
     const gfx::Size& resolution_in_pixels) {
-  if (display_info_.find(display_id) == display_info_.end()) {
-    display_info_[display_id] =
-        DisplayInfo(display_id, std::string(""), false);
-  }
+  if (display_info_.find(display_id) == display_info_.end())
+    display_info_[display_id] = DisplayInfo(display_id, std::string(), false);
 
   display_info_[display_id].set_rotation(rotation);
   // Just in case the preference file was corrupted.
@@ -705,7 +703,6 @@ void DisplayManager::UpdateDisplays(
           (current_display_info.size_in_pixel() !=
            new_display.GetSizeInPixel()) ||
           (current_display.rotation() != new_display.rotation())) {
-
         changed_display_indices.push_back(new_displays.size());
       }
 
@@ -975,9 +972,9 @@ void DisplayManager::AddMirrorDisplayInfoIfAny(
 void DisplayManager::InsertAndUpdateDisplayInfo(const DisplayInfo& new_info) {
   std::map<int64, DisplayInfo>::iterator info =
       display_info_.find(new_info.id());
-  if (info != display_info_.end())
+  if (info != display_info_.end()) {
     info->second.Copy(new_info);
-  else {
+  } else {
     display_info_[new_info.id()] = new_info;
     display_info_[new_info.id()].set_native(false);
   }
@@ -1015,7 +1012,7 @@ bool DisplayManager::UpdateSecondaryDisplayBoundsForLayout(
       (id_at_zero == first_display_id_ ||
        id_at_zero == gfx::Display::InternalDisplayId()) ?
       std::make_pair(id_at_zero, displays->at(1).id()) :
-      std::make_pair(displays->at(1).id(), id_at_zero) ;
+      std::make_pair(displays->at(1).id(), id_at_zero);
   DisplayLayout layout =
       layout_store_->ComputeDisplayLayoutForDisplayIdPair(pair);
 

chrome/browser/chromeos/system/syslogs_provider.cc

@@ -51,17 +51,17 @@ const char kContextNetwork[] = "network";
 // Reads a key from the input string erasing the read values + delimiters read
 // from the initial string
 std::string ReadKey(std::string* data) {
+  std::string key;
   size_t equal_sign = data->find("=");
   if (equal_sign == std::string::npos)
-    return std::string("");
-  std::string key = data->substr(0, equal_sign);
+    return key;
+  key = data->substr(0, equal_sign);
   data->erase(0, equal_sign);
-  if (data->size() > 0) {
+  if (data->empty())
+    return key;
   // erase the equal to sign also
-    data->erase(0,1);
+  data->erase(0, 1);
   return key;
-  }
-  return std::string();
 }
 
 // Reads a value from the input string; erasing the read values from
@@ -93,7 +93,8 @@ std::string ReadValue(std::string* data) {
     std::string value = data->substr(0, next_multi);
     data->erase(0, next_multi + 3);
     return value;
-  } else { // single line value
+  } else {
+    // single line value
     size_t endl_pos = data->find_first_of(kNewLineChars);
     // if we don't find a new line, we just return the rest of the data
     std::string value = data->substr(0, endl_pos);

chromeos/network/network_configuration_handler_unittest.cc

@@ -359,7 +359,7 @@ TEST_F(NetworkConfigurationHandlerTest, CreateConfiguration) {
   network_configuration_handler_->CreateConfiguration(
       value,
       base::Bind(&StringResultCallback, std::string("/service/2")),
-      base::Bind(&ErrorCallback, false, std::string("")));
+      base::Bind(&ErrorCallback, false, std::string()));
   message_loop_.RunUntilIdle();
 }
 

gpu/command_buffer/common/debug_marker_manager.cc

@@ -21,7 +21,7 @@ void DebugMarkerManager::Group::SetMarker(const std::string& marker) {
 
 DebugMarkerManager::DebugMarkerManager() {
   // Push root group.
-  group_stack_.push(Group(std::string("")));
+  group_stack_.push(Group(std::string()));
 }
 
 DebugMarkerManager::~DebugMarkerManager() {

net/cert/ct_serialization_unittest.cc

@@ -94,7 +94,7 @@ TEST_F(CtSerializationTest, EncodesV1SCTSignedData) {
   base::Time timestamp = base::Time::UnixEpoch() +
       base::TimeDelta::FromMilliseconds(1348589665525);
   std::string dummy_entry("abc");
-  std::string empty_extensions("");
+  std::string empty_extensions;
   // For now, no known failure cases.
   std::string encoded;
   ASSERT_TRUE(ct::EncodeV1SCTSignedData(
@@ -145,7 +145,7 @@ TEST_F(CtSerializationTest, DecodesSignedCertificateTimestamp) {
   // Subtracting 4 bytes for signature data (hash & sig algs),
   // actual signature data should be 71 bytes.
   EXPECT_EQ((size_t) 71, sct->signature.signature_data.size());
-  EXPECT_EQ(std::string(""), sct->extensions);
+  EXPECT_TRUE(sct->extensions.empty());
 }
 
 TEST_F(CtSerializationTest, FailsDecodingInvalidSignedCertificateTimestamp) {