Implementation of GetFavicon for current tab.

chrome/browser/android/tab_android.cc

Index: chrome/browser/android/tab_android.cc
diff --git a/chrome/browser/android/tab_android.cc b/chrome/browser/android/tab_android.cc
index 4b1a8762b9090705d026b1fa8c153ba9d59ed6d3..503f42980e6d796044d0397bdf92a20b0e725c65 100644
--- a/chrome/browser/android/tab_android.cc
+++ b/chrome/browser/android/tab_android.cc
@@ -12,6 +12,7 @@
 #include "chrome/browser/browser_about_handler.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/content_settings/tab_specific_content_settings.h"
+#include "chrome/browser/favicon/favicon_tab_helper.h"
 #include "chrome/browser/google/google_url_tracker_factory.h"
 #include "chrome/browser/infobars/infobar_service.h"
 #include "chrome/browser/prerender/prerender_contents.h"
@@ -46,7 +47,13 @@
 #include "content/public/browser/user_metrics.h"
 #include "content/public/browser/web_contents.h"
 #include "jni/Tab_jni.h"
+#include "skia/ext/image_operations.h"
 #include "third_party/WebKit/public/platform/WebReferrerPolicy.h"
+#include "ui/base/resource/resource_bundle.h"
+#include "ui/gfx/android/device_display_info.h"
+#include "ui/gfx/android/java_bitmap.h"
+#include "ui/gfx/favicon_size.h"
+#include "ui/gfx/image/image_skia.h"
 
 TabAndroid* TabAndroid::FromWebContents(content::WebContents* web_contents) {
   CoreTabHelper* core_tab_helper = CoreTabHelper::FromWebContents(web_contents);
@@ -511,6 +518,42 @@ bool TabAndroid::Print(JNIEnv* env, jobject obj) {
   return true;
 }
 
+ScopedJavaLocalRef<jobject> TabAndroid::GetFavicon(JNIEnv* env, jobject obj) {
+  ScopedJavaLocalRef<jobject> bitmap;
+  FaviconTabHelper* favicon_tab_helper =
+      FaviconTabHelper::FromWebContents(web_contents_.get());
+  if (!favicon_tab_helper)
+    return bitmap;
+  if (!favicon_tab_helper->FaviconIsValid())
+    return bitmap;
+
+  SkBitmap favicon =
+      favicon_tab_helper->GetFavicon()
+          .AsImageSkia()
+          .GetRepresentation(
+               ResourceBundle::GetSharedInstance().GetMaxScaleFactor())
+          .sk_bitmap();
+
+  if (!favicon.isNull()) {

[David Trainor- moved to gerrit, 2014/07/28 17:50:05]

I think IsEmpty() might be better here

Also, f favicon is empty we should fall back to icon.AsBitmap().  If one of
those isn't empty then we should perform the appropriate scaling and return
it... this will never fall back to a default favicon if we don't have the
correct density.

[Jitu( very slow this week), 2014/07/30 11:33:56]

We can't do check IsEmpty() here as favicon is type SkBitmap.

Sorry 
Are you talking about only IsEmpty() check or anything else which i can't
interpreted.

Or do you want i have to changes like

gfx::Image favicon = favicon_tab_helper->GetFavicon().image;

And then check if favicon is not empty then do the scaling.

Please let me know in case any misunderstood. 

[David Trainor- moved to gerrit, 2014/07/30 17:51:23]

Ah sorry!  I meant SkBitmap.empty() not IsEmpty()...

On 2014/07/30 11:33:56, Jitu wrote:

+    gfx::DeviceDisplayInfo device_info;
+    const float device_scale_factor = device_info.GetDIPScale();
+    int target_size_dip = device_scale_factor * gfx::kFaviconSize;
+    if (favicon.width() != target_size_dip ||
+        favicon.height() != target_size_dip)

[David Trainor- moved to gerrit, 2014/07/28 17:50:04]

Use {} this seems somewhat hard to read.

[Jitu( very slow this week), 2014/07/30 11:33:56]

Done.

+      favicon =
+          skia::ImageOperations::Resize(favicon,
+                                        skia::ImageOperations::RESIZE_BEST,
+                                        target_size_dip,
+                                        target_size_dip);
+
+  } else {
+    gfx::Image image;
+    favicon = image.AsBitmap();
+  }
+  bitmap = gfx::ConvertToJavaBitmap(&favicon);
+  return bitmap;
+}
+
 prerender::PrerenderManager* TabAndroid::GetPrerenderManager() const {
   Profile* profile = GetProfile();
   if (!profile)