Generate thumbnails in the browser process.

chrome/browser/tab_contents/thumbnail_generator.h

Index: chrome/browser/tab_contents/thumbnail_generator.h
diff --git a/chrome/browser/tab_contents/thumbnail_generator.h b/chrome/browser/tab_contents/thumbnail_generator.h
index 335b2cbcd8e4ea75f1aaa4ea4e32b3bd488f3635..c6e4cbcb6c7bc74e69ce1ed373c2f898e910bc6c 100644
--- a/chrome/browser/tab_contents/thumbnail_generator.h
+++ b/chrome/browser/tab_contents/thumbnail_generator.h
@@ -26,6 +26,39 @@ class TabContents;
 class ThumbnailGenerator : NotificationObserver {
  public:
   typedef Callback1<const SkBitmap&>::Type ThumbnailReadyCallback;
+  // The result of clipping. This can be used to determine if the
+  // generated thumbnail is good or not.
+  enum ClipResult {
+    // The source image is smaller.
+    kSourceIsSmaller,
+    // Wider than tall, clip horizontally.
+    kWiderThanTall,
+    // Taller than wide, clip vertically.
+    kTallerThanWide,
+    // The source and destination aspect ratios are identical.
+    kNotClipped,
+  };
+
+  // Bitmasks of options for generating a thumbnail.
+  enum ThumbnailOptions {
+    // No options.
+    kNone = 0,
+    // Request a clipped thumbnail with the aspect ratio preserved.
+    kClippedThumbnail = 1 << 0,
+    // Calculate the boring score.
+    kBoringScore = 1 << 1,
+  };
+
+  // The result of thumbnailing.
+  struct ThumbnailResult {
+    ThumbnailResult() : clip_result(kNotClipped), boring_score(0.0) {}
+
+    ClipResult clip_result;
+    // The boring score is the 0,1 ranged percentage of boringness. Higher
+    // boring scores indicate that the generated thumbnail is more like empty.
+    double boring_score;
+  };
+
   // This class will do nothing until you call StartThumbnailing.
   ThumbnailGenerator();
   ~ThumbnailGenerator();
@@ -61,6 +94,14 @@ class ThumbnailGenerator : NotificationObserver {
   // renderer.
   SkBitmap GetThumbnailForRenderer(RenderWidgetHost* renderer) const;
 
+  // This returns a thumbnail of a fixed, small size for the given
+  // renderer. |options| is a bitmask of ThumbnailOptions. If
+  // |thumbnail_result| is non-NULL, additional information like the
+  // boring boring score will be stored in it.
+  SkBitmap GetThumbnailForRendererWithOptions(RenderWidgetHost* renderer,
+                                              int options,
+                                              ThumbnailResult* result) const;
+
   // Start or stop monitoring notifications for |renderer| based on the value
   // of |monitor|.
   void MonitorRenderer(RenderWidgetHost* renderer, bool monitor);