Allow load if play() is immediately called when preload == 'none'

This fixes a bug where the load gets blocked by preload == 'none'
eventhough JavaScript has called play() after setting the src
attribute. This particular bug only appears if play() is called before
the JavaScript code relinquishes control back to the UA.

Tests cases were added to make sure that immediate load() and play()
calls both trigger loading. Before this change, only immediate load()
calls ignored the preload == "none" state.

BUG=177870
TEST=LayoutTest/media/video-preload.html

Review URL: https://codereview.chromium.org/313173008

git-svn-id: svn://svn.chromium.org/blink/trunk@175590 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/LayoutTests/media/video-preload-expected.txt

@@ -11,9 +11,27 @@ EVENT(play)
 EVENT(loadedmetadata)
 buffered automatically OK
 
+Will load with 'preload=none', should buffer automatically because 'load()' is called
+RUN(video.setAttribute('preload', 'none'))
+RUN(video.removeAttribute('autoplay'))
+RUN(video.load())
+EVENT(loadstart)
+EVENT(loadedmetadata)
+buffered automatically OK
+
+Will load with 'preload=none', should buffer automatically because 'play()' is called
+RUN(video.setAttribute('preload', 'none'))
+RUN(video.removeAttribute('autoplay'))
+RUN(video.play())
+EVENT(play)
+EVENT(loadstart)
+EVENT(loadedmetadata)
+buffered automatically OK
+
 Will load with 'preload=metadata', should buffer automatically 
 RUN(video.setAttribute('preload', 'metadata'))
 RUN(video.removeAttribute('autoplay'))
+RUN(video.load())
 EVENT(loadstart)
 EVENT(loadedmetadata)
 buffered automatically OK
@@ -21,6 +39,7 @@ buffered automatically OK
 Will load with 'preload=auto', should buffer automatically 
 RUN(video.setAttribute('preload', 'auto'))
 RUN(video.removeAttribute('autoplay'))
+RUN(video.load())
 EVENT(loadstart)
 EVENT(loadedmetadata)
 buffered automatically OK
@@ -28,6 +47,7 @@ buffered automatically OK
 Will load with 'preload=none', should buffer automatically because of 'autoplay'
 RUN(video.setAttribute('preload', 'none'))
 RUN(video.setAttribute('autoplay', 'true'))
+RUN(video.load())
 EVENT(loadstart)
 EVENT(loadedmetadata)
 buffered automatically OK

third_party/WebKit/LayoutTests/media/video-preload.html

@@ -7,36 +7,56 @@
 
         <script>
             var timer = null;
-            var movieInfo = 
+            var movieInfo =
             {
                 current : -1,
-                movies : 
-                [ 
+                movies :
+                [
                     {
                         // should not buffer, 'preload' is 'none'
                         preload : "none",
                         shouldBuffer : false,
                         autoPlay : false,
-                        description : "until 'play()' is called", 
+                        playInsteadOfLoad : false,
+                        description : "until 'play()' is called",
+                    },
+                    {
+                        // should buffer, because load() is called.
+                        preload : "none",
+                        shouldBuffer : true,
+                        autoPlay : false,
+                        playInsteadOfLoad : false,
+                        description : "because 'load()' is called",
+                    },
+                    {
+                        // should buffer, because play() is called.
+                        preload : "none",
+                        shouldBuffer : true,
+                        autoPlay : false,
+                        playInsteadOfLoad : true,
+                        description : "because 'play()' is called",
                     },
                     {
                         preload : "metadata",
                         shouldBuffer : true,
                         autoPlay : false,
-                        description : "", 
+                        playInsteadOfLoad : false,
+                        description : "",
                     },
                     {
                         preload : "auto",
                         shouldBuffer : true,
                         autoPlay : false,
-                        description : "", 
+                        playInsteadOfLoad : false,
+                        description : "",
                     },
                     {
                         // should buffer because 'autoplay' is set
                         preload : "none",
                         shouldBuffer : true,
                         autoPlay : true,
-                        description : " because of 'autoplay'", 
+                        playInsteadOfLoad : false,
+                        description : " because of 'autoplay'",
                     },
                 ]
             };
@@ -47,7 +67,7 @@
                 var movie = movieInfo.movies[movieInfo.current];
 
                 logResult(true, "did not buffer automatically");
-                
+
                 // start playback, which should force data to load
                 movie.shouldBuffer = true;
                 run("video.play()");
@@ -92,12 +112,17 @@
                 setupAttribute('autoplay', movie.autoPlay);
 
                 video.src = url;
-                if (movieInfo.current > 0)
-                    video.load();
+                if (movieInfo.current > 0) {
+                    if (movie.playInsteadOfLoad) {
+                        run("video.play()");
+                    } else {
+                        run("video.load()");
+                    }
+                }
                 if (!movie.shouldBuffer)
                     timer = setTimeout(checkLoad, 200);
             }
-            
+
             function start()
             {
                 findMediaElement();
@@ -106,7 +131,7 @@
                 waitForEvent("loadstart");
                 waitForEvent("play");
                 waitForEvent('loadedmetadata', loadedmetadata);
-            
+
                 openNextMovie();
             }
 

third_party/WebKit/Source/core/html/HTMLMediaElement.cpp

@@ -889,10 +889,12 @@ void HTMLMediaElement::loadResource(const KURL& url, ContentType& contentType, c
     if (attemptLoad && canLoadURL(url, contentType, keySystem)) {
         ASSERT(!webMediaPlayer());
 
-        if (!autoplay() && m_preload == MediaPlayer::None)
+        if (!m_havePreparedToPlay && !autoplay() && m_preload == MediaPlayer::None) {
+            WTF_LOG(Media, "HTMLMediaElement::loadResource : Delaying load because preload == 'none'");
             m_delayingLoadForPreloadNone = true;
-        else
+        } else {
             startPlayerLoad();
+        }
     } else {
         mediaLoadingFailed(MediaPlayer::FormatError);
     }