Fix blurry favicons fetches on Android

This change depends on https://codereview.chromium.org/12041064/
Introduces a new scale factor for Nexus 7: SCALE_FACTOR_133P.
Uses max available density on Android instead of SCALE_FACTOR_100P.

BUG=172048
NOTRY=true

Review URL: https://chromiumcodereview.appspot.com/12084003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@180518 0039d316-1c4b-4281-b951-d872f2087c98

8 files changed, 55 insertions, 28 deletions

diff --git a/chrome/browser/android/provider/chrome_browser_provider.cc b/chrome/browser/android/provider/chrome_browser_provider.cc
index cdfd468..6285eac 100644
--- a/chrome/browser/android/provider/chrome_browser_provider.cc
+++ b/chrome/browser/android/provider/chrome_browser_provider.cc
@@ -654,7 +654,7 @@ class BookmarkIconFetchTask : public FaviconServiceTask {
                        url,
                        history::FAVICON | history::TOUCH_ICON,
                        gfx::kFaviconSize),
-                   ui::SCALE_FACTOR_100P,
+                   ui::GetMaxScaleFactor(),
                    base::Bind(
                        &BookmarkIconFetchTask::OnFaviconRetrieved,
                        base::Unretained(this)),
diff --git a/chrome/browser/resources/ntp_android/ntp_android.js b/chrome/browser/resources/ntp_android/ntp_android.js
index 963dcb3..ff99293 100644
--- a/chrome/browser/resources/ntp_android/ntp_android.js
+++ b/chrome/browser/resources/ntp_android/ntp_android.js
@@ -582,7 +582,11 @@ cr.define('ntp', function() {
 
     cell.setAttribute(CONTEXT_MENU_URL_KEY, item.url);
 
-    var iconUrl = item.icon || 'chrome://touch-icon/size/16@1x/' + item.url;
+    var iconUrl = item.icon;
+    if (!iconUrl) {
+      iconUrl = 'chrome://touch-icon/size/16@' + window.devicePixelRatio +
+          'x/' + item.url;
+    }
     var icon = createDiv('icon', iconUrl);
     trackImageLoad(iconUrl);
     cell.appendChild(icon);
@@ -676,7 +680,7 @@ cr.define('ntp', function() {
     if (item.folder) {
       faviconBox.classList.add('folder');
     } else {
-      var iconUrl = item.icon || 'chrome://touch-icon/' + item.url;
+      var iconUrl = item.icon || 'chrome://touch-icon/largest/' + item.url;
       var faviconIcon = createDiv('favicon-icon');
       faviconIcon.style.backgroundImage = 'url(' + iconUrl + ')';
       trackImageLoad(iconUrl);
@@ -686,8 +690,10 @@ cr.define('ntp', function() {
       image.onload = function() {
         var w = image.width;
         var h = image.height;
-        if (w <= 16 || h <= 16) {
-          // it's a standard favicon (or at least it's small)
+        var wDip = w / window.devicePixelRatio;
+        var hDip = h / window.devicePixelRatio;
+        if (Math.floor(wDip) <= 16 || Math.floor(hDip) <= 16) {
+          // it's a standard favicon (or at least it's small).
           faviconBox.classList.add('document');
 
           faviconBox.appendChild(
@@ -704,21 +710,26 @@ cr.define('ntp', function() {
           foldContainer.appendChild(foldDiv);
           faviconBox.appendChild(foldContainer);
 
+          // FaviconWebUIHandler::HandleGetFaviconDominantColor expects
+          // an URL that starts with chrome://favicon/size/.
+          // The handler always loads 16x16 1x favicon and assumes that
+          // the dominant color for all scale factors is the same.
           chrome.send('getFaviconDominantColor',
               [('chrome://favicon/size/16@1x/' + item.url), '' + faviconIndex]);
           faviconIndex++;
         } else if ((w == 57 && h == 57) || (w == 114 && h == 114)) {
-          // it's a touch icon
+          // it's a touch icon for 1x or 2x.
           faviconIcon.classList.add('touch-icon');
         } else {
-          // it's an html5 icon (or at least it's larger)
-          var max = 64;
-          if (w > max || h > max) {
-            var scale = (w > h) ? (max / w) : (max / h);
-            w *= scale;
-            h *= scale;
+          // It's an html5 icon (or at least it's larger).
+          // Rescale it to be no bigger than 64x64 dip.
+          var maxDip = 64; // DIP
+          if (wDip > maxDip || hDip > maxDip) {
+            var scale = (wDip > hDip) ? (maxDip / wDip) : (maxDip / hDip);
+            wDip *= scale;
+            hDip *= scale;
           }
-          faviconIcon.style.backgroundSize = w + 'px ' + h + 'px';
+          faviconIcon.style.backgroundSize = wDip + 'px ' + hDip + 'px';
         }
       };
       faviconBox.appendChild(faviconIcon);
diff --git a/chrome/browser/ui/webui/favicon_source.cc b/chrome/browser/ui/webui/favicon_source.cc
index 628afc6..c498b33 100644
--- a/chrome/browser/ui/webui/favicon_source.cc
+++ b/chrome/browser/ui/webui/favicon_source.cc
@@ -22,9 +22,10 @@ namespace {
 
 // Parameters which can be used in chrome://favicon path. See .h file for a
 // description of what each does.
-const char kSizeParameter[] = "size/";
 const char kIconURLParameter[] = "iconurl/";
+const char kLargestParameter[] = "largest/";
 const char kOriginParameter[] = "origin/";
+const char kSizeParameter[] = "size/";
 
 // Returns true if |search| is a substring of |path| which starts at
 // |start_index|.
@@ -92,7 +93,10 @@ void FaviconSource::StartDataRequest(
   ui::ScaleFactor scale_factor = ui::SCALE_FACTOR_100P;
 
   size_t parsed_index = 0;
-  if (HasSubstringAt(path, parsed_index, kSizeParameter)) {
+  if (HasSubstringAt(path, parsed_index, kLargestParameter)) {
+    parsed_index += strlen(kLargestParameter);
+    size_in_dip = 0;
+  } else if (HasSubstringAt(path, parsed_index, kSizeParameter)) {
     parsed_index += strlen(kSizeParameter);
 
     size_t scale_delimiter = path.find("@", parsed_index);
@@ -123,7 +127,13 @@ void FaviconSource::StartDataRequest(
                                         slash - scale_delimiter - 1);
     webui::ParseScaleFactor(scale_str, &scale_factor);
 
-    if (scale_factor != ui::SCALE_FACTOR_100P && size_in_dip != 16) {
+    // Return the default favicon (as opposed to a resized favicon) for
+    // favicon sizes which are not cached by the favicon service.
+    // Currently the favicon service caches:
+    // - favicons of sizes "16 * scale factor" px of type FAVICON
+    //   where scale factor is one of FaviconUtil::GetFaviconScaleFactors().
+    // - the largest TOUCH_ICON / TOUCH_PRECOMPOSED_ICON
+    if (size_in_dip != 16 && icon_types_ == history::FAVICON) {
       SendDefaultResponse(callback);
       return;
     }
diff --git a/chrome/browser/ui/webui/favicon_source.h b/chrome/browser/ui/webui/favicon_source.h
index 02eae11..eb34b02 100644
--- a/chrome/browser/ui/webui/favicon_source.h
+++ b/chrome/browser/ui/webui/favicon_source.h
@@ -30,13 +30,17 @@ class Profile;
 //    Specifies the page URL of the requested favicon. If the 'urlmodifier'
 //    parameter is 'iconurl', the URL refers to the URL of the favicon image
 //    instead.
-//  'size&scalefactor'  Optional  size/aa@bx/
-//    Specifies the requested favicon's size in DIP (aa) and the requested
-//    favicon's scale factor. (b).
-//    The supported requested DIP sizes are: 16x16, 32x32 and 64x64.
-//    If the parameter is unspecified, the requested favicon's size defaults to
-//    16 and the requested scale factor defaults to 1x.
-//    Example: chrome://favicon/size/16@2x/http://www.google.com/
+//  'size&scalefactor'  Optional
+//    Values: ['largest', size/aa@bx/]
+//    'largest': Specifies that the largest available favicon is requested.
+//      Example: chrome://favicon/largest/http://www.google.com/
+//    'size/aa@bx/':
+//      Specifies the requested favicon's size in DIP (aa) and the requested
+//      favicon's scale factor. (b).
+//      The supported requested DIP sizes are: 16x16, 32x32 and 64x64.
+//      If the parameter is unspecified, the requested favicon's size defaults
+//      to 16 and the requested scale factor defaults to 1x.
+//      Example: chrome://favicon/size/16@2x/http://www.google.com/
 //  'urlmodifier'      Optional
 //    Values: ['iconurl', 'origin']
 //    'iconurl': Specifies that the url parameter refers to the URL of
diff --git a/chrome/browser/ui/webui/ntp/android/bookmarks_handler.cc b/chrome/browser/ui/webui/ntp/android/bookmarks_handler.cc
index bcde01a..606f8dc 100644
--- a/chrome/browser/ui/webui/ntp/android/bookmarks_handler.cc
+++ b/chrome/browser/ui/webui/ntp/android/bookmarks_handler.cc
@@ -391,7 +391,7 @@ void BookmarksHandler::HandleCreateHomeScreenBookmarkShortcut(
           node->url(),
           history::FAVICON | history::TOUCH_ICON,
           gfx::kFaviconSize),
-      ui::SCALE_FACTOR_100P,
+      ui::GetMaxScaleFactor(),
       base::Bind(&BookmarksHandler::OnShortcutFaviconDataAvailable,
                  base::Unretained(this),
                  node),
diff --git a/ui/base/layout.cc b/ui/base/layout.cc
index 2175fac..f68b1ed 100644
--- a/ui/base/layout.cc
+++ b/ui/base/layout.cc
@@ -65,7 +65,7 @@ bool UseTouchOptimizedUI() {
 }
 #endif  // defined(OS_WIN)
 
-const float kScaleFactorScales[] = {1.0f, 1.0f, 1.4f, 1.5f, 1.8f, 2.0f};
+const float kScaleFactorScales[] = {1.0f, 1.0f, 1.33f, 1.4f, 1.5f, 1.8f, 2.0f};
 COMPILE_ASSERT(NUM_SCALE_FACTORS == arraysize(kScaleFactorScales),
                kScaleFactorScales_incorrect_size);
 const size_t kScaleFactorScalesLength = arraysize(kScaleFactorScales);
diff --git a/ui/base/layout.h b/ui/base/layout.h
index c8c278d..236e58e 100644
--- a/ui/base/layout.h
+++ b/ui/base/layout.h
@@ -36,6 +36,7 @@ UI_EXPORT DisplayLayout GetDisplayLayout();
 enum ScaleFactor {
   SCALE_FACTOR_NONE = 0,
   SCALE_FACTOR_100P,
+  SCALE_FACTOR_133P,
   SCALE_FACTOR_140P,
   SCALE_FACTOR_150P,
   SCALE_FACTOR_180P,
diff --git a/ui/base/layout_unittest.cc b/ui/base/layout_unittest.cc
index 13f2794..3153f97 100644
--- a/ui/base/layout_unittest.cc
+++ b/ui/base/layout_unittest.cc
@@ -16,6 +16,7 @@ namespace ui {
 
 TEST(LayoutTest, GetScaleFactorScale) {
   EXPECT_FLOAT_EQ(1.0f, GetScaleFactorScale(SCALE_FACTOR_100P));
+  EXPECT_FLOAT_EQ(1.33f, GetScaleFactorScale(SCALE_FACTOR_133P));
   EXPECT_FLOAT_EQ(1.4f, GetScaleFactorScale(SCALE_FACTOR_140P));
   EXPECT_FLOAT_EQ(1.5f, GetScaleFactorScale(SCALE_FACTOR_150P));
   EXPECT_FLOAT_EQ(1.8f, GetScaleFactorScale(SCALE_FACTOR_180P));
@@ -47,9 +48,9 @@ TEST(LayoutTest, GetScaleFactorFromScaleAllSupported) {
   EXPECT_EQ(SCALE_FACTOR_100P, GetScaleFactorFromScale(0.1f));
   EXPECT_EQ(SCALE_FACTOR_100P, GetScaleFactorFromScale(0.9f));
   EXPECT_EQ(SCALE_FACTOR_100P, GetScaleFactorFromScale(1.0f));
-  EXPECT_EQ(SCALE_FACTOR_100P, GetScaleFactorFromScale(1.19f));
-  EXPECT_EQ(SCALE_FACTOR_140P, GetScaleFactorFromScale(1.21f));
-  EXPECT_EQ(SCALE_FACTOR_140P, GetScaleFactorFromScale(1.3f));
+  EXPECT_EQ(SCALE_FACTOR_133P, GetScaleFactorFromScale(1.19f));
+  EXPECT_EQ(SCALE_FACTOR_133P, GetScaleFactorFromScale(1.21f));
+  EXPECT_EQ(SCALE_FACTOR_133P, GetScaleFactorFromScale(1.3f));
   EXPECT_EQ(SCALE_FACTOR_140P, GetScaleFactorFromScale(1.4f));
   EXPECT_EQ(SCALE_FACTOR_150P, GetScaleFactorFromScale(1.59f));
   EXPECT_EQ(SCALE_FACTOR_150P, GetScaleFactorFromScale(1.61f));