Various optimizations to reduce the number of temporary allocations.

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/files/file.h"
 #include "base/memory/ref_counted_memory.h"
@@ skipping 82 matching lines @@
   // supposed to be changeable by the user.
   const char* key;
 };
 
 // IDR_* resource names change whenever new resources are added; use persistent
 // IDs when storing to a cached pack.
 //
 // TODO(erg): The cocoa port is the last user of the IDR_*_[HP] variants. These
 // should be removed once the cocoa port no longer uses them.
 PersistingImagesTable kPersistingImages[] = {
   { PRS_THEME_FRAME, IDR_THEME_FRAME,

[Sigurður Ásgeirsson, 2014/11/25 01:37:01]

it should be easy to mandate these be in-order and to use a unittest to make
sure it's so - in which case the search in log(n).

     "theme_frame" },
   { PRS_THEME_FRAME_INACTIVE, IDR_THEME_FRAME_INACTIVE,
     "theme_frame_inactive" },
   { PRS_THEME_FRAME_INCOGNITO, IDR_THEME_FRAME_INCOGNITO,
     "theme_frame_incognito" },
   { PRS_THEME_FRAME_INCOGNITO_INACTIVE, IDR_THEME_FRAME_INCOGNITO_INACTIVE,
     "theme_frame_incognito_inactive" },
   { PRS_THEME_TOOLBAR, IDR_THEME_TOOLBAR,
     "theme_toolbar" },
   { PRS_THEME_TAB_BACKGROUND, IDR_THEME_TAB_BACKGROUND,
@@ skipping 672 matching lines @@
   result->clear();
   for (size_t i = 0; i < kPersistingImagesLength; ++i)
     result->insert(kPersistingImages[i].idr_id);
 
 #if defined(USE_ASH) && !defined(OS_CHROMEOS)
   for (size_t i = 0; i < kPersistingImagesDesktopAuraLength; ++i)
     result->insert(kPersistingImagesDesktopAura[i].idr_id);
 #endif
 }
 
+// static
+bool BrowserThemePack::FindThemeableImageIDRs(int id) {
+  for (size_t i = 0; i < kPersistingImagesLength; ++i)
+    if (kPersistingImages[i].idr_id == id)
+      return true;
+
+#if defined(USE_ASH) && !defined(OS_CHROMEOS)
+  for (size_t i = 0; i < kPersistingImagesDesktopAuraLength; ++i)
+    if (kPersistingImagesDesktopAura[i].idr_id == id)
+      return true;
+#endif
+
+  return false;
+}
+
 bool BrowserThemePack::WriteToDisk(const base::FilePath& path) const {
   // 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(
       reinterpret_cast<const char*>(tints_),
       sizeof(TintEntry[kTintTableLength]));
   resources[kColorsID] = base::StringPiece(
       reinterpret_cast<const char*>(colors_),
@@ skipping 823 matching lines @@
                                            false,
                                            &bitmap_data)) {
       NOTREACHED() << "Unable to encode theme image for prs_id="
                    << prs_id << " for scale_factor=" << scale_factors_[i];
       break;
     }
     image_memory_[scaled_raw_id] =
         base::RefCountedBytes::TakeVector(&bitmap_data);
   }
 }