Fixes for getting themes to work well with Windows High DPI.

The changes are to use the GetScaleForScaleFactor function to get the scale instead
of GetImageScale. The latter function returns the current display scale on Windows which
causes themes to break. The other change is in the ctor of the BrowserThemePack class
where we add SCALE_FACTOR_100P to the list of supported scales as it is needed for default
theme packs to work correctly.

BUG=362979
R=oshima@chromium.org, pkotwicz@chromium.org, oshima

Review URL: https://codereview.chromium.org/296643002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@271999 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/themes/browser_theme_pack.cc

@@ -244,7 +244,7 @@ bool InputScalesValid(const base::StringPiece& input,
   // Do a memcpy to avoid misaligned memory access.
   memcpy(scales.get(), input.data(), input.size());
   for (size_t index = 0; index < scales_size; ++index) {
-    if (scales[index] != ui::GetImageScale(expected[index]))
+    if (scales[index] != ui::GetScaleForScaleFactor(expected[index]))
       return false;
   }
   return true;
@@ -255,7 +255,7 @@ std::string GetScaleFactorsAsString(
     const std::vector<ui::ScaleFactor>& scale_factors) {
   scoped_ptr<float[]> scales(new float[scale_factors.size()]);
   for (size_t i = 0; i < scale_factors.size(); ++i)
-    scales[i] = ui::GetImageScale(scale_factors[i]);
+    scales[i] = ui::GetScaleForScaleFactor(scale_factors[i]);
   std::string out_string = std::string(
       reinterpret_cast<const char*>(scales.get()),
       scale_factors.size() * sizeof(float));
@@ -451,8 +451,8 @@ SkBitmap CreateLowQualityResizedBitmap(const SkBitmap& source_bitmap,
   gfx::Size scaled_size = gfx::ToCeiledSize(
       gfx::ScaleSize(gfx::Size(source_bitmap.width(),
                                source_bitmap.height()),
-                     ui::GetImageScale(desired_scale_factor) /
-                     ui::GetImageScale(source_scale_factor)));
+                     ui::GetScaleForScaleFactor(desired_scale_factor) /
+                     ui::GetScaleForScaleFactor(source_scale_factor)));
   SkBitmap scaled_bitmap;
   scaled_bitmap.setConfig(SkBitmap::kARGB_8888_Config,
                           scaled_size.width(),
@@ -535,8 +535,8 @@ class ThemeImagePngSource : public gfx::ImageSkiaSource {
     for (PngMap::const_iterator png_it = png_map_.begin();
          png_it != png_map_.end(); ++png_it) {
       if (available_png_it == png_map_.end() ||
-          ui::GetImageScale(png_it->first) >
-          ui::GetImageScale(available_png_it->first)) {
+          ui::GetScaleForScaleFactor(png_it->first) >
+          ui::GetScaleForScaleFactor(available_png_it->first)) {
         available_png_it = png_it;
       }
     }
@@ -756,6 +756,7 @@ scoped_refptr<BrowserThemePack> BrowserThemePack::BuildFromDataPack(
   if (!InputScalesValid(pointer, pack->scale_factors_)) {
     DLOG(ERROR) << "BuildFromDataPack failure! The pack scale factors differ "
                 << "from those supported by platform.";
+    return NULL;
   }
   return pack;
 }
@@ -926,6 +927,11 @@ BrowserThemePack::BrowserThemePack()
       display_properties_(NULL),
       source_images_(NULL) {
   scale_factors_ = ui::GetSupportedScaleFactors();
+  // On Windows with high DPI SCALE_FACTOR_100P may not be supported by
+  // default.
+  // Add it to the supported scale factors list as themes needs it.
+  if (!ui::IsScaleFactorSupported(ui::SCALE_FACTOR_100P))
+    scale_factors_.push_back(ui::SCALE_FACTOR_100P);
 }
 
 void BrowserThemePack::BuildHeader(const Extension* extension) {
@@ -1282,7 +1288,7 @@ bool BrowserThemePack::LoadRawBitmapsTo(
                                     &bitmap)) {
             image_skia.AddRepresentation(
                 gfx::ImageSkiaRep(bitmap,
-                                  ui::GetImageScale(scale_factor)));
+                                  ui::GetScaleForScaleFactor(scale_factor)));
           } else {
             NOTREACHED() << "Unable to decode theme image resource "
                          << it->first;
@@ -1531,7 +1537,8 @@ bool BrowserThemePack::GetScaleFactorFromManifestKey(
   if (base::StringToInt(key, &percent)) {
     float scale = static_cast<float>(percent) / 100.0f;
     for (size_t i = 0; i < scale_factors_.size(); ++i) {
-      if (fabs(ui::GetImageScale(scale_factors_[i]) - scale) < 0.001) {
+      if (fabs(ui::GetScaleForScaleFactor(scale_factors_[i]) - scale)
+              < 0.001) {
         *scale_factor = scale_factors_[i];
         return true;
       }
@@ -1568,8 +1575,8 @@ void BrowserThemePack::GenerateRawImageForAllSupportedScales(int prs_id) {
   for (size_t i = 0; i < scale_factors_.size(); ++i) {
     int raw_id = GetRawIDByPersistentID(prs_id, scale_factors_[i]);
     if ((available_scale_factor == ui::SCALE_FACTOR_NONE ||
-         (ui::GetImageScale(scale_factors_[i]) >
-          ui::GetImageScale(available_scale_factor))) &&
+         (ui::GetScaleForScaleFactor(scale_factors_[i]) >
+          ui::GetScaleForScaleFactor(available_scale_factor))) &&
         image_memory_.find(raw_id) != image_memory_.end()) {
       available_scale_factor = scale_factors_[i];
     }