fixing some texture update issues

Source/WebCore/platform/graphics/texmap/TextureMapperGL.cpp

@@ -426,6 +426,9 @@ static bool driverSupportsBGRASwizzling()
 {
 #if defined(TEXMAP_OPENGL_ES_2)
     // FIXME: Implement reliable detection. See also https://bugs.webkit.org/show_bug.cgi?id=81103.
+    if(strstr((char*)glGetString(GL_EXTENSIONS), " GL_EXT_texture_format_BGRA8888 ")) {
+        return true;
+    }
     return false;
 #else
     return true;
@@ -473,9 +476,12 @@ void BitmapTextureGL::updateContents(const void* data, const IntRect& targetRect
     else
         swizzleBGRAToRGBA(reinterpret_cast<uint32_t*>(const_cast<void*>(data)), IntRect(sourceOffset, targetRect.size()), bytesPerLine / 4);
 
-    if (bytesPerLine == targetRect.width() / 4 && sourceOffset == IntPoint::zero()) {
+    if (bytesPerLine == targetRect.width() * 4 && sourceOffset == IntPoint::zero()) {
         GL_CMD(glTexSubImage2D(GL_TEXTURE_2D, 0, targetRect.x(), targetRect.y(), targetRect.width(), targetRect.height(), glFormat, DEFAULT_TEXTURE_PIXEL_TRANSFER_TYPE, (const char*)data));
         return;
+    } else if (bytesPerLine == targetRect.width() * 3 && sourceOffset == IntPoint::zero()) {
+        GL_CMD(glTexSubImage2D(GL_TEXTURE_2D, 0, targetRect.x(), targetRect.y(), targetRect.width(), targetRect.height(), GL_RGB, DEFAULT_TEXTURE_PIXEL_TRANSFER_TYPE, (const char*)data));
+        return;
     }
 
     // For ES drivers that don't support sub-images, transfer the pixels row-by-row.
@@ -520,6 +526,15 @@ void BitmapTextureGL::updateContents(Image* image, const IntRect& targetRect, co
     // This might be a deep copy, depending on other references to the pixmap.
     qtImage = frameImage->toImage();
 #endif
+
+    if(qtImage.hasAlphaChannel() && isOpaque()) {
+        // upgrade the texture to RGBA
+        reset(size(), BitmapTexture::SupportsAlpha);
+    } else if (!qtImage.hasAlphaChannel() && !isOpaque()) {
+        //downgrade to RGB
+        reset(size()); //defaults to no alpha!
+    }
+
     imageData = reinterpret_cast<const char*>(qtImage.constBits());
     bytesPerLine = qtImage.bytesPerLine();
 #elif USE(CAIRO)