Fixes memory alignment issues due to browser_theme_pack changes

chrome/browser/themes/browser_theme_pack.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/themes/browser_theme_pack.h"
 
 #include <limits>
 
 #include "base/memory/ref_counted_memory.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 170 matching lines @@
       int prs_id = kPersistingImages[i].persistent_id;
       (*lookup_table)[idr] = prs_id;
     }
   }
   std::map<int,int>::iterator it = lookup_table->find(idr);
   return (it == lookup_table->end()) ? -1 : it->second;
 }
 
 // Returns true if the scales in |input| match those in |expected|.
 // The order must match as the index is used in determining the raw id.
-bool InputScalesValid(const char* input,
+bool InputScalesValid(const base::StringPiece& input,
                       const std::vector<ui::ScaleFactor>& expected) {
-  const float* scales = reinterpret_cast<const float*>(input);
+  size_t scales_size = static_cast<size_t>(
+      input.size() * sizeof(char) / sizeof(float));

[benrg, 2012/08/09 21:45:10]

Either don't multiply by sizeof(char) here or else do divide by it on line 216.
:-)

+  float* scales = new float[scales_size];

[sky, 2012/08/09 19:49:17]

scoped_array here and 211 (200/202 leak the way you have it now).

[benrg, 2012/08/09 21:45:10]

I think there should be a comment explaining why this copy is needed --
otherwise someone will try to remove it some day.

+  memcpy(scales, input.data(), input.size());
   size_t index = 0;
-  for (const float* end = scales; *end != -1.0f; ++end) {
+  for (; index < scales_size; ++index) {
     if (index >= expected.size())

[benrg, 2012/08/09 21:45:10]

It would be slightly simpler to check scales_size == expected.size() up front
and remove this check and the one on line 205. (And merge line 197 into line
198.)

       return false;
-    if (*end != ui::GetScaleFactorScale(expected[index]))
+    if (scales[index] != ui::GetScaleFactorScale(expected[index]))
       return false;
-    index++;
   }
+  delete[] scales;
   return (index == expected.size());
 }
 
 // Returns |scale_factors| as a string to be written to disk.
 std::string GetScaleFactorsAsString(
     const std::vector<ui::ScaleFactor>& scale_factors) {
-  size_t scales_size = scale_factors.size() + 1;
-  float* scales = new float[scales_size];
+  float* scales = new float[scale_factors.size()];
   for (size_t i = 0; i < scale_factors.size(); ++i)
     scales[i] = ui::GetScaleFactorScale(scale_factors[i]);
-  scales[scales_size - 1] = -1.0f;
   std::string out_string = std::string(
       reinterpret_cast<const char*>(scales),
-      scales_size * sizeof(float));
+      scale_factors.size() * sizeof(float));
   delete[] scales;
   return out_string;
 }
 
 struct StringToIntTable {
   const char* key;
   int id;
 };
 
 // Strings used by themes to identify tints in the JSON.
@@ skipping 275 matching lines @@
       const_cast<char*>(pointer.data()));
 
   if (!pack->data_pack_->GetStringPiece(kSourceImagesID, &pointer))
     return NULL;
   pack->source_images_ = reinterpret_cast<int*>(
       const_cast<char*>(pointer.data()));
 
   if (!pack->data_pack_->GetStringPiece(kScaleFactorsID, &pointer))
     return NULL;
 
-  if (!InputScalesValid(const_cast<char*>(pointer.data()),
-                        pack->scale_factors_)) {
+  if (!InputScalesValid(pointer, pack->scale_factors_)) {
     DLOG(ERROR) << "BuildFromDataPack failure! The pack scale factors differ "
                 << "from those supported by platform.";
   }
-
   return pack;
 }
 
 bool BrowserThemePack::WriteToDisk(const FilePath& path) const {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   // Add resources for each of the property arrays.
   RawDataForWriting resources;
   resources[kHeaderID] = base::StringPiece(
       reinterpret_cast<const char*>(header_), sizeof(BrowserThemePackHeader));
   resources[kTintsID] = base::StringPiece(
@@ skipping 705 matching lines @@
     ui::ScaleFactor scale_factor) const {
   if (prs_id < 0)
     return -1;
 
   for (size_t i = 0; i < scale_factors_.size(); ++i) {
     if (scale_factors_[i] == scale_factor)
       return static_cast<int>(kPersistingImagesLength * i) + prs_id;
   }
   return -1;
 }