Untemplatize PDFiumAPIStringBufferSizeInBytesAdapter.

This templatized class is only ever used for base::string16. Since that
is the only string type it will be used with in the foreseeable future,
remove the overhead of the template.

Change-Id: I7a62e83ab612c1d7e7b2461a50bc7be7be0768f9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2207737
Reviewed-by: Daniel Hosseinian <dhoss@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#770809}

pdf/pdfium/pdfium_api_string_buffer_adapter.cc

@@ -9,7 +9,6 @@
 #include <string>
 
 #include "base/check_op.h"
-#include "base/strings/string16.h"
 #include "base/strings/string_util.h"
 
 namespace chrome_pdf {
@@ -52,36 +51,28 @@ void PDFiumAPIStringBufferAdapter<StringType>::Close(size_t actual_size) {
   }
 }
 
-template <class StringType>
-PDFiumAPIStringBufferSizeInBytesAdapter<StringType>::
-    PDFiumAPIStringBufferSizeInBytesAdapter(StringType* str,
+PDFiumAPIStringBufferSizeInBytesAdapter::
+    PDFiumAPIStringBufferSizeInBytesAdapter(base::string16* str,
                                             size_t expected_size,
                                             bool check_expected_size)
-    : adapter_(str,
-               expected_size / sizeof(typename StringType::value_type),
-               check_expected_size) {
-  DCHECK(expected_size % sizeof(typename StringType::value_type) == 0);
+    : adapter_(str, expected_size / sizeof(base::char16), check_expected_size) {
+  DCHECK(expected_size % sizeof(base::char16) == 0);
 }
 
-template <class StringType>
-PDFiumAPIStringBufferSizeInBytesAdapter<
-    StringType>::~PDFiumAPIStringBufferSizeInBytesAdapter() = default;
+PDFiumAPIStringBufferSizeInBytesAdapter::
+    ~PDFiumAPIStringBufferSizeInBytesAdapter() = default;
 
-template <class StringType>
-void* PDFiumAPIStringBufferSizeInBytesAdapter<StringType>::GetData() {
+void* PDFiumAPIStringBufferSizeInBytesAdapter::GetData() {
   return adapter_.GetData();
 }
 
-template <class StringType>
-void PDFiumAPIStringBufferSizeInBytesAdapter<StringType>::Close(
-    size_t actual_size) {
-  DCHECK(actual_size % sizeof(typename StringType::value_type) == 0);
-  adapter_.Close(actual_size / sizeof(typename StringType::value_type));
+void PDFiumAPIStringBufferSizeInBytesAdapter::Close(size_t actual_size) {
+  DCHECK(actual_size % sizeof(base::char16) == 0);
+  adapter_.Close(actual_size / sizeof(base::char16));
 }
 
 // explicit instantiations
 template class PDFiumAPIStringBufferAdapter<std::string>;
 template class PDFiumAPIStringBufferAdapter<base::string16>;
-template class PDFiumAPIStringBufferSizeInBytesAdapter<base::string16>;
 
 }  // namespace chrome_pdf

pdf/pdfium/pdfium_api_string_buffer_adapter.h

@@ -9,14 +9,14 @@
 
 #include "base/macros.h"
 #include "base/numerics/safe_math.h"
+#include "base/strings/string16.h"
 
 namespace chrome_pdf {
 
 // Helper to deal with the fact that many PDFium APIs write the null-terminator
-// into string buffers that are passed to them, but the PDF plugin likes to pass
-// in std::strings / base::string16s, where one should not count on the internal
+// into string buffers that are passed to them, but the PDF code likes to use
+// std::strings / base::string16s, where one should not count on the internal
 // string buffers to be null-terminated.
-
 template <class StringType>
 class PDFiumAPIStringBufferAdapter {
  public:
@@ -56,11 +56,11 @@ class PDFiumAPIStringBufferAdapter {
 };
 
 // Helper to deal with the fact that many PDFium APIs write the null-terminator
-// into string buffers that are passed to them, but the PDF plugin likes to pass
-// in std::strings / base::string16s, where one should not count on the internal
+// into string buffers that are passed to them, but the PDF code likes to use
+// std::strings / base::string16s, where one should not count on the internal
 // string buffers to be null-terminated. This version is suitable for APIs that
-// work in terms of number of bytes instead of the number of characters.
-template <class StringType>
+// work in terms of number of bytes instead of the number of characters. Though
+// for std::strings, PDFiumAPIStringBufferAdapter is equivalent.
 class PDFiumAPIStringBufferSizeInBytesAdapter {
  public:
   // |str| is the string to write into.
@@ -69,19 +69,19 @@ class PDFiumAPIStringBufferSizeInBytesAdapter {
   // character in bytes.
   // |check_expected_size| whether to check the actual number of bytes
   // written into |str| against |expected_size| when calling Close().
-  PDFiumAPIStringBufferSizeInBytesAdapter(StringType* str,
+  PDFiumAPIStringBufferSizeInBytesAdapter(base::string16* str,
                                           size_t expected_size,
                                           bool check_expected_size);
   ~PDFiumAPIStringBufferSizeInBytesAdapter();
 
   // Returns a pointer to |str_|'s buffer. The buffer's size is large enough to
-  // hold |expected_size_| + sizeof(StringType::value_type) bytes, so the PDFium
-  // API that uses the pointer has space to write a null-terminator.
+  // hold |expected_size_| + sizeof(base::char16) bytes, so the PDFium API that
+  // uses the pointer has space to write a null-terminator.
   void* GetData();
 
-  // Resizes |str_| to |actual_size| - sizeof(StringType::value_type) bytes,
-  // thereby removing the extra null-terminator. This must be called prior to
-  // the adapter's destruction. The pointer returned by GetData() should be
+  // Resizes |str_| to |actual_size| - sizeof(base::char16) bytes, thereby
+  // removing the extra null-terminator. This must be called prior to the
+  // adapter's destruction. The pointer returned by GetData() should be
   // considered invalid.
   void Close(size_t actual_size);
 
@@ -91,7 +91,7 @@ class PDFiumAPIStringBufferSizeInBytesAdapter {
   }
 
  private:
-  PDFiumAPIStringBufferAdapter<StringType> adapter_;
+  PDFiumAPIStringBufferAdapter<base::string16> adapter_;
 };
 
 }  // namespace chrome_pdf

pdf/pdfium/pdfium_engine.cc

@@ -1000,7 +1000,7 @@ void PDFiumEngine::SetFormSelectedText(FPDF_FORMHANDLE form_handle,
     return;
 
   base::string16 selected_form_text16;
-  PDFiumAPIStringBufferSizeInBytesAdapter<base::string16> string_adapter(
+  PDFiumAPIStringBufferSizeInBytesAdapter string_adapter(
       &selected_form_text16, form_sel_text_len, false);
   string_adapter.Close(FORM_GetSelectedText(
       form_handle, page, string_adapter.GetData(), form_sel_text_len));
@@ -2147,7 +2147,7 @@ pp::VarDictionary PDFiumEngine::TraverseBookmarks(FPDF_BOOKMARK bookmark,
   base::string16 title;
   unsigned long buffer_size = FPDFBookmark_GetTitle(bookmark, nullptr, 0);
   if (buffer_size > 0) {
-    PDFiumAPIStringBufferSizeInBytesAdapter<base::string16> api_string_adapter(
+    PDFiumAPIStringBufferSizeInBytesAdapter api_string_adapter(
         &title, buffer_size, true);
     api_string_adapter.Close(FPDFBookmark_GetTitle(
         bookmark, api_string_adapter.GetData(), buffer_size));
@@ -3802,7 +3802,7 @@ std::string PDFiumEngine::GetMetadataByField(FPDF_BYTESTRING field) const {
     return std::string();
 
   base::string16 value;
-  PDFiumAPIStringBufferSizeInBytesAdapter<base::string16> string_adapter(
+  PDFiumAPIStringBufferSizeInBytesAdapter string_adapter(
       &value, size, /*check_expected_size=*/false);
   string_adapter.Close(
       FPDF_GetMetaText(doc(), field, string_adapter.GetData(), size));

pdf/pdfium/pdfium_page.cc

@@ -195,7 +195,7 @@ std::string GetFormFieldProperty(GetFormFieldPropertyFunction function) {
   base::string16 data;
   size_t buffer_size = function.Run(nullptr, 0);
   if (buffer_size > 0) {
-    PDFiumAPIStringBufferSizeInBytesAdapter<base::string16> api_string_adapter(
+    PDFiumAPIStringBufferSizeInBytesAdapter api_string_adapter(
         &data, buffer_size, true);
     api_string_adapter.Close(function.Run(
         reinterpret_cast<unsigned short*>(api_string_adapter.GetData()),
@@ -1157,8 +1157,8 @@ void PDFiumPage::PopulateImageAltTextForStructElement(
           FPDF_StructElement_GetAltText(current_element, nullptr, 0);
       if (buffer_size > 0) {
         base::string16 alt_text;
-        PDFiumAPIStringBufferSizeInBytesAdapter<base::string16>
-            api_string_adapter(&alt_text, buffer_size, true);
+        PDFiumAPIStringBufferSizeInBytesAdapter api_string_adapter(
+            &alt_text, buffer_size, true);
         api_string_adapter.Close(FPDF_StructElement_GetAltText(
             current_element, api_string_adapter.GetData(), buffer_size));
         images_[it->second].alt_text = base::UTF16ToUTF8(alt_text);