Plugin Power Saver: Implement pixel tests for plugin placeholders.

chrome/browser/plugins/plugin_power_saver_browsertest.cc

Index: chrome/browser/plugins/plugin_power_saver_browsertest.cc
diff --git a/chrome/browser/plugins/plugin_power_saver_browsertest.cc b/chrome/browser/plugins/plugin_power_saver_browsertest.cc
index 0c1959d2da7bb786a37e10492e554a3ac053cd8d..fce95a537f2d0e444f1b9984b84bbac53eea4c58 100644
--- a/chrome/browser/plugins/plugin_power_saver_browsertest.cc
+++ b/chrome/browser/plugins/plugin_power_saver_browsertest.cc
@@ -2,15 +2,24 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <string>
+
 #include "base/command_line.h"
+#include "base/stl_util.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/stringprintf.h"
 #include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/test/base/in_process_browser_test.h"
+#include "chrome/test/base/test_switches.h"
 #include "chrome/test/base/ui_test_utils.h"
 #include "components/ui/zoom/zoom_controller.h"
+#include "content/public/browser/readback_types.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/render_view_host.h"
+#include "content/public/browser/render_widget_host.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/test/browser_test_utils.h"
 #include "content/public/test/ppapi_test_utils.h"
@@ -19,11 +28,28 @@
 #include "net/test/embedded_test_server/http_response.h"
 #include "ppapi/shared_impl/ppapi_switches.h"
 #include "third_party/WebKit/public/web/WebInputEvent.h"
+#include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/base/window_open_disposition.h"
+#include "ui/gfx/codec/png_codec.h"
 #include "ui/gfx/geometry/point.h"
+#include "ui/gfx/screen.h"
 
 namespace {
 
+// Use fixed browser dimensions for pixel tests.
+const int kBrowserWidth = 600;
+const int kBrowserHeight = 700;
+
+// Compare only a portion of the snapshots, as different platforms will
+// capture different sized snapshots (due to differences in browser chrome).
+const int kComparisonWidth = 500;
+const int kComparisonHeight = 600;
+
+// Different platforms have slightly different pixel output, due to different
+// graphics implementations. Slightly different pixels (in BGR space) are still
+// counted as a matching pixel by this simple manhattan distance threshold.
+const int kPixelManhattanDistanceTolerance = 8;
+
 std::string RunTestScript(base::StringPiece test_script,
                           content::WebContents* contents,
                           const std::string& element_id) {
@@ -43,7 +69,8 @@ std::string RunTestScript(base::StringPiece test_script,
 }
 
 // This also tests that we have JavaScript access to the underlying plugin.
-bool PluginLoaded(content::WebContents* contents, const char* element_id) {
+bool PluginLoaded(content::WebContents* contents,
+                  const std::string& element_id) {
   std::string result = RunTestScript(
       "if (plugin.postMessage === undefined) {"
       "  window.domAutomationController.send('poster_only');"
@@ -55,9 +82,28 @@ bool PluginLoaded(content::WebContents* contents, const char* element_id) {
   return result == "plugin_loaded";
 }
 
+// Blocks until the placeholder is ready.
+void WaitForPlaceholderReady(content::WebContents* contents,
+                             const std::string& element_id) {
+  std::string result = RunTestScript(
+      "function handleEvent(event) {"
+      "  if (event.data === 'placeholderReady') {"
+      "    window.domAutomationController.send('ready');"
+      "    plugin.removeEventListener('message', handleEvent);"
+      "  }"
+      "}"
+      "plugin.addEventListener('message', handleEvent);"
+      "if (plugin.hasAttribute('placeholderReady')) {"
+      "  window.domAutomationController.send('ready');"
+      "  plugin.removeEventListener('message', handleEvent);"
+      "}",
+      contents, element_id);
+  ASSERT_EQ("ready", result);
+}
+
 // Also waits for the placeholder UI overlay to finish loading.
 void VerifyPluginIsThrottled(content::WebContents* contents,
-                             const char* element_id) {
+                             const std::string& element_id) {
   std::string result = RunTestScript(
       "function handleEvent(event) {"
       "  if (event.data.isPeripheral && event.data.isThrottled && "
@@ -75,10 +121,12 @@ void VerifyPluginIsThrottled(content::WebContents* contents,
 
   // Page should continue to have JavaScript access to all throttled plugins.
   EXPECT_TRUE(PluginLoaded(contents, element_id));
+
+  WaitForPlaceholderReady(contents, element_id);
 }
 
 void VerifyPluginMarkedEssential(content::WebContents* contents,
-                                 const char* element_id) {
+                                 const std::string& element_id) {
   std::string result = RunTestScript(
       "function handleEvent(event) {"
       "  if (event.data.isPeripheral === false) {"
@@ -105,13 +153,118 @@ scoped_ptr<net::test_server::HttpResponse> RespondWithHTML(
   return response.Pass();
 }
 
+void VerifyVisualStateUpdated(const base::Closure& done_cb,
+                              bool visual_state_updated) {
+  ASSERT_TRUE(visual_state_updated);
+  done_cb.Run();
+}
+
+bool SnapshotMatches(const base::FilePath& reference, const SkBitmap& bitmap) {
+  if (bitmap.width() < kComparisonWidth ||
+      bitmap.height() < kComparisonHeight) {
+    return false;
+  }
+
+  std::string reference_data;
+  if (!base::ReadFileToString(reference, &reference_data))
+    return false;
+
+  int w = 0;
+  int h = 0;
+  std::vector<unsigned char> decoded;
+  if (!gfx::PNGCodec::Decode(
+          reinterpret_cast<unsigned char*>(string_as_array(&reference_data)),
+          reference_data.size(), gfx::PNGCodec::FORMAT_BGRA, &decoded, &w,
+          &h)) {
+    return false;
+  }
+
+  if (w < kComparisonWidth || h < kComparisonHeight)
+    return false;
+
+  int32_t* ref_pixels = reinterpret_cast<int32_t*>(vector_as_array(&decoded));
+  SkAutoLockPixels lock_image(bitmap);
+  int32_t* pixels = static_cast<int32_t*>(bitmap.getPixels());
+
+  int stride = bitmap.rowBytes();
+  for (int y = 0; y < kComparisonHeight; ++y) {
+    for (int x = 0; x < kComparisonWidth; ++x) {
+      int32_t pixel = pixels[y * stride / sizeof(int32_t) + x];
+      int pixel_b = pixel & 0xFF;
+      int pixel_g = (pixel >> 8) & 0xFF;
+      int pixel_r = (pixel >> 16) & 0xFF;
+
+      int32_t ref_pixel = ref_pixels[y * w + x];
+      int ref_pixel_b = ref_pixel & 0xFF;
+      int ref_pixel_g = (ref_pixel >> 8) & 0xFF;
+      int ref_pixel_r = (ref_pixel >> 16) & 0xFF;
+
+      int manhattan_distance = abs(pixel_b - ref_pixel_b) +
+                               abs(pixel_g - ref_pixel_g) +
+                               abs(pixel_r - ref_pixel_r);
+
+      if (manhattan_distance > kPixelManhattanDistanceTolerance)
+        return false;
+    }
+  }
+
+  return true;
+}
+
+// |snapshot_matches| is set to true if the snapshot matches the reference and
+// the test passes. Otherwise, set to false.
+void CompareSnapshotToReference(const base::FilePath& reference,
+                                bool* snapshot_matches,
+                                const base::Closure& done_cb,
+                                const SkBitmap& bitmap,
+                                content::ReadbackResponse response) {
+  DCHECK(snapshot_matches);
+  if (response != content::READBACK_SUCCESS) {
+    *snapshot_matches = false;
+    done_cb.Run();
+    return;
+  }
+
+  *snapshot_matches = SnapshotMatches(reference, bitmap);
+
+  // When rebaselining the pixel test, the test will fail, and we will
+  // overwrite the reference file. On the next try through, the test will then
+  // pass, since we just overwrote the reference file. A bit wonky.
+  if (!(*snapshot_matches) &&
+      base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kRebaselinePixelTests)) {
+    SkBitmap clipped_bitmap;
+    bitmap.extractSubset(&clipped_bitmap,
+                         SkIRect::MakeWH(kComparisonWidth, kComparisonHeight));
+    std::vector<unsigned char> png_data;
+    ASSERT_TRUE(
+        gfx::PNGCodec::EncodeBGRASkBitmap(clipped_bitmap, false, &png_data));
+    ASSERT_EQ(static_cast<int>(png_data.size()),
+              base::WriteFile(reference, reinterpret_cast<const char*>(
+                                             vector_as_array(&png_data)),
+                              png_data.size()));
+  }
+
+  done_cb.Run();
+}
+
 }  // namespace
 
 class PluginPowerSaverBrowserTest : public InProcessBrowserTest {
  public:
+  void SetUp() override {
+    EnablePixelOutput();
+    InProcessBrowserTest::SetUp();
+  }
+
   void SetUpOnMainThread() override {
     InProcessBrowserTest::SetUpOnMainThread();
     ASSERT_TRUE(embedded_test_server()->InitializeAndWaitUntilReady());
+
+    embedded_test_server()->ServeFilesFromDirectory(
+        ui_test_utils::GetTestFilePath(
+            base::FilePath(FILE_PATH_LITERAL("plugin_power_saver")),
+            base::FilePath()));
   }
 
   void SetUpCommandLine(base::CommandLine* command_line) override {
@@ -126,6 +279,13 @@ class PluginPowerSaverBrowserTest : public InProcessBrowserTest {
 
  protected:
   void LoadHTML(const std::string& html) {
+    gfx::Rect bounds(gfx::Rect(0, 0, kBrowserWidth, kBrowserHeight));
+    gfx::Rect screen_bounds =
+        gfx::Screen::GetNativeScreen()->GetPrimaryDisplay().bounds();
+    ASSERT_GT(screen_bounds.width(), kBrowserWidth);
+    ASSERT_GT(screen_bounds.height(), kBrowserHeight);
+    browser()->window()->SetBounds(bounds);
+
     ASSERT_TRUE(embedded_test_server()->Started());
     embedded_test_server()->RegisterRequestHandler(
         base::Bind(&RespondWithHTML, html));
@@ -145,29 +305,51 @@ class PluginPowerSaverBrowserTest : public InProcessBrowserTest {
   //  - Peripheral status change.
   //  - In response to the explicit 'getPowerSaverStatus' request, in case the
   //    test has missed the above two events.
-  void SimulateClickAndAwaitMarkedEssential(const char* element_id,
+  void SimulateClickAndAwaitMarkedEssential(const std::string& element_id,
                                             const gfx::Point& point) {
-    // Waits for the placeholder to be ready to be clicked first.
-    std::string result = RunTestScript(
-        "function handleEvent(event) {"
-        "  if (event.data === 'placeholderLoaded') {"
-        "    window.domAutomationController.send('ready');"
-        "    plugin.removeEventListener('message', handleEvent);"
-        "  }"
-        "}"
-        "plugin.addEventListener('message', handleEvent);"
-        "if (plugin.hasAttribute('placeholderLoaded')) {"
-        "  window.domAutomationController.send('ready');"
-        "  plugin.removeEventListener('message', handleEvent);"
-        "}",
-        GetActiveWebContents(), element_id);
-    ASSERT_EQ("ready", result);
-
+    WaitForPlaceholderReady(GetActiveWebContents(), element_id);
     content::SimulateMouseClickAt(GetActiveWebContents(), 0 /* modifiers */,
                                   blink::WebMouseEvent::ButtonLeft, point);
 
     VerifyPluginMarkedEssential(GetActiveWebContents(), element_id);
   }
+
+  // |element_id| must be an element on the foreground tab.
+  void VerifyPluginIsPosterOnly(const std::string& element_id) {
+    EXPECT_FALSE(PluginLoaded(GetActiveWebContents(), element_id));
+    WaitForPlaceholderReady(GetActiveWebContents(), element_id);
+  }
+
+  bool VerifySnapshot(const base::FilePath::StringType& expected_filename) {
+    base::FilePath reference = ui_test_utils::GetTestFilePath(
+        base::FilePath(FILE_PATH_LITERAL("plugin_power_saver")),
+        base::FilePath(expected_filename));
+
+    GetActiveWebContents()->GetMainFrame()->InsertVisualStateCallback(
+        base::Bind(&VerifyVisualStateUpdated,
+                   base::MessageLoop::QuitWhenIdleClosure()));
+    content::RunMessageLoop();
+
+    content::RenderWidgetHost* rwh =
+        GetActiveWebContents()->GetRenderViewHost()->GetWidget();
+
+    // When a widget is first shown, it can take some time before it is ready
+    // for copying from its backing store.  This is a transient condition, and
+    // so it is not being treated as a test failure.
+    if (!rwh->CanCopyFromBackingStore())
+      return false;
+
+    bool snapshot_matches = false;
+    rwh->CopyFromBackingStore(
+        gfx::Rect(), gfx::Size(),
+        base::Bind(&CompareSnapshotToReference, reference, &snapshot_matches,
+                   base::MessageLoop::QuitWhenIdleClosure()),
+        kN32_SkColorType);
+
+    content::RunMessageLoop();
+
+    return snapshot_matches;
+  }
 };
 
 IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, SmallSameOrigin) {
@@ -182,10 +364,21 @@ IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, SmallCrossOrigin) {
   LoadHTML(
       "<object id='plugin' data='http://otherorigin.com/fake.swf' "
       "    type='application/x-ppapi-tests' width='400' height='100'>"
+      "</object>"
+      "<br>"
+      "<object id='plugin_poster' data='http://otherorigin.com/fake.swf' "
+      "    type='application/x-ppapi-tests' width='400' height='100' "
+      "    poster='click_me.png'>"
       "</object>");
+
   VerifyPluginIsThrottled(GetActiveWebContents(), "plugin");
+  VerifyPluginIsPosterOnly("plugin_poster");
+
+  EXPECT_TRUE(
+      VerifySnapshot(FILE_PATH_LITERAL("small_cross_origin_expected.png")));
 
   SimulateClickAndAwaitMarkedEssential("plugin", gfx::Point(50, 50));
+  SimulateClickAndAwaitMarkedEssential("plugin_poster", gfx::Point(50, 150));
 }
 
 IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, LargeCrossOrigin) {
@@ -200,6 +393,96 @@ IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, LargeCrossOrigin) {
   VerifyPluginMarkedEssential(GetActiveWebContents(), "medium_16_9");
 }
 
+IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, SmallerThanPlayIcon) {
+  LoadHTML(
+      "<object id='plugin_16' type='application/x-ppapi-tests' "
+      "    width='16' height='16'></object>"
+      "<object id='plugin_32' type='application/x-ppapi-tests' "
+      "    width='32' height='32'></object>"
+      "<object id='plugin_16_64' type='application/x-ppapi-tests' "
+      "    width='16' height='64'></object>"
+      "<object id='plugin_64_16' type='application/x-ppapi-tests' "
+      "    width='64' height='16'></object>");
+
+  VerifyPluginIsThrottled(GetActiveWebContents(), "plugin_16");
+  VerifyPluginIsThrottled(GetActiveWebContents(), "plugin_32");
+  VerifyPluginIsThrottled(GetActiveWebContents(), "plugin_16_64");
+  VerifyPluginIsThrottled(GetActiveWebContents(), "plugin_64_16");
+
+  EXPECT_TRUE(
+      VerifySnapshot(FILE_PATH_LITERAL("smaller_than_play_icon_expected.png")));
+}
+
+IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, PosterTests) {
+  // This test simultaneously verifies the varied supported poster syntaxes,
+  // as well as verifies that the poster is rendered correctly with various
+  // mismatched aspect ratios and sizes, following the same rules as VIDEO.
+  LoadHTML(
+      "<object id='plugin_src' type='application/x-ppapi-tests' "
+      "    width='100' height='100' poster='click_me.png'></object>"
+      "<object id='plugin_srcset' type='application/x-ppapi-tests' "
+      "    width='100' height='100' "
+      "    poster='click_me.png 1x, click_me.png 2x'></object>"
+      "<br>"
+
+      "<object id='plugin_poster_param' type='application/x-ppapi-tests' "
+      "    width='100' height='100'>"
+      "  <param name='poster' value='click_me.png 1x, click_me.png 2x'>"
+      "</object>"
+      "<embed id='plugin_embed_src' type='application/x-ppapi-tests' "
+      "    width='100' height='100' poster='click_me.png'></embed>"
+      "<embed id='plugin_embed_srcset' type='application/x-ppapi-tests' "
+      "    width='100' height='100'"
+      "    poster='click_me.png 1x, click_me.png 2x'></embed>"
+      "<br>"
+
+      "<object id='poster_missing' type='application/x-ppapi-tests' "
+      "    width='100' height='100' poster='missing.png'></object>"
+      "<object id='poster_too_small' type='application/x-ppapi-tests' "
+      "    width='100' height='50' poster='click_me.png'></object>"
+      "<object id='poster_too_big' type='application/x-ppapi-tests' "
+      "    width='100' height='150' poster='click_me.png'></object>"
+      "<br>"
+
+      "<object id='poster_16' type='application/x-ppapi-tests' "
+      "    width='16' height='16' poster='click_me.png'></object>"
+      "<object id='poster_32' type='application/x-ppapi-tests' "
+      "    width='32' height='32' poster='click_me.png'></object>"
+      "<object id='poster_16_64' type='application/x-ppapi-tests' "
+      "    width='16' height='64' poster='click_me.png'></object>"
+      "<object id='poster_64_16' type='application/x-ppapi-tests' "
+      "    width='64' height='16' poster='click_me.png'></object>"
+      "<br>"
+
+      "<div id='container' "
+      "    style='width: 400px; height: 100px; overflow: hidden;'>"
+      "  <object id='poster_obscured' data='http://otherorigin.com/fake.swf' "
+      "      type='application/x-ppapi-tests' width='400' height='500' "
+      "      poster='click_me.png'>"
+      "  </object>"
+      "</div>");
+
+  VerifyPluginIsPosterOnly("plugin_src");
+  VerifyPluginIsPosterOnly("plugin_srcset");
+
+  VerifyPluginIsPosterOnly("plugin_poster_param");
+  VerifyPluginIsPosterOnly("plugin_embed_src");
+  VerifyPluginIsPosterOnly("plugin_embed_srcset");
+
+  VerifyPluginIsPosterOnly("poster_missing");
+  VerifyPluginIsPosterOnly("poster_too_small");
+  VerifyPluginIsPosterOnly("poster_too_big");
+
+  VerifyPluginIsPosterOnly("poster_16");
+  VerifyPluginIsPosterOnly("poster_32");
+  VerifyPluginIsPosterOnly("poster_16_64");
+  VerifyPluginIsPosterOnly("poster_64_16");
+
+  VerifyPluginIsPosterOnly("poster_obscured");
+
+  EXPECT_TRUE(VerifySnapshot(FILE_PATH_LITERAL("poster_tests_expected.png")));
+}
+
 IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, LargePostersNotThrottled) {
   // This test verifies that small posters are throttled, large posters are not,
   // and that large posters can whitelist origins for other plugins.
@@ -217,7 +500,7 @@ IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, LargePostersNotThrottled) {
       "    type='application/x-ppapi-tests' width='400' height='300' "
       "    poster='click_me.png'></object>");
 
-  EXPECT_FALSE(PluginLoaded(GetActiveWebContents(), "poster_small"));
+  VerifyPluginIsPosterOnly("poster_small");
   VerifyPluginMarkedEssential(GetActiveWebContents(),
                               "poster_whitelisted_origin");
   VerifyPluginMarkedEssential(GetActiveWebContents(),
@@ -230,7 +513,7 @@ IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest,
   LoadHTML(
       "<object id='plugin' type='application/x-ppapi-tests' "
       "    width='400' height='100' poster='snapshot1x.png'></object>");
-  EXPECT_FALSE(PluginLoaded(GetActiveWebContents(), "plugin"));
+  VerifyPluginIsPosterOnly("plugin");
 
   SimulateClickAndAwaitMarkedEssential("plugin", gfx::Point(50, 50));
 }
@@ -253,12 +536,15 @@ IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, OriginWhitelisting) {
 IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, LargeCrossOriginObscured) {
   LoadHTML(
       "<div id='container' "
-      "    style='width: 400px; height: 100px; overflow: hidden;'>"
+      "    style='width: 100px; height: 400px; overflow: hidden;'>"
       "  <object id='plugin' data='http://otherorigin.com/fake.swf' "
-      "      type='application/x-ppapi-tests' width='400' height='500'>"
+      "      type='application/x-ppapi-tests' width='400' height='500' "
+      "      style='float: right;'>"
       "  </object>"
       "</div>");
   VerifyPluginIsThrottled(GetActiveWebContents(), "plugin");
+  EXPECT_TRUE(VerifySnapshot(
+      FILE_PATH_LITERAL("large_cross_origin_obscured_expected.png")));
 
   // Test that's unthrottled if it is unobscured.
   std::string script =