Add canvas context type histogram

Add canvas context type histogram

Add histogram for tracking which names are being used to create canvas
rendering contexts.

BUG=112928
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=155620

[Mark P, 2013-08-02 15:40:55]

https://codereview.chromium.org/21861002/diff/1/Source/core/html/HTMLCanvasEl...
File Source/core/html/HTMLCanvasElement.cpp (right):

https://codereview.chromium.org/21861002/diff/1/Source/core/html/HTMLCanvasEl...
Source/core/html/HTMLCanvasElement.cpp:162: };
Please add a note that new elements should only be added at the end and that
existing elements should not be reordered.

[Sami, 2013-08-02 16:05:25]

https://codereview.chromium.org/21861002/diff/1/Source/core/html/HTMLCanvasEl...
File Source/core/html/HTMLCanvasElement.cpp (right):

https://codereview.chromium.org/21861002/diff/1/Source/core/html/HTMLCanvasEl...
Source/core/html/HTMLCanvasElement.cpp:162: };
On 2013/08/02 15:40:55, Mark P wrote:
> Please add a note that new elements should only be added at the end and that
> existing elements should not be reordered.

Done.

[Mark P, 2013-08-02 22:39:03]

On 2013/08/02 16:05:25, Sami wrote:
>
https://codereview.chromium.org/21861002/diff/1/Source/core/html/HTMLCanvasEl...
> File Source/core/html/HTMLCanvasElement.cpp (right):
> 
>
https://codereview.chromium.org/21861002/diff/1/Source/core/html/HTMLCanvasEl...
> Source/core/html/HTMLCanvasElement.cpp:162: };
> On 2013/08/02 15:40:55, Mark P wrote:
> > Please add a note that new elements should only be added at the end and that
> > existing elements should not be reordered.
> 
> Done.

Thanks.

I'll now remove myself as a reviewer; I'm not qualified to comment on anything
else on this change.

[Ken Russell (switch to Gerrit), 2013-08-05 21:11:26]

lgtm

[commit-bot: I haz the power, 2013-08-06 10:12:09]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/skyostil@chromium.org/21861002/5001

[commit-bot: I haz the power, 2013-08-06 10:12:19]

Failed to apply patch for Source/core/html/HTMLCanvasElement.cpp:
While running patch -p1 --forward --force --no-backup-if-mismatch;
  patching file Source/core/html/HTMLCanvasElement.cpp
  Hunk #1 succeeded at 42 with fuzz 2 (offset 3 lines).
  Hunk #2 succeeded at 152 (offset -1 lines).
  Hunk #3 succeeded at 168 (offset -1 lines).
  Hunk #4 FAILED at 179.
  1 out of 4 hunks FAILED -- saving rejects to file
Source/core/html/HTMLCanvasElement.cpp.rej

Patch:       Source/core/html/HTMLCanvasElement.cpp
Index: Source/core/html/HTMLCanvasElement.cpp
diff --git a/Source/core/html/HTMLCanvasElement.cpp
b/Source/core/html/HTMLCanvasElement.cpp
index
20be42fdda8dafac636a49de66da9d208560df53..71ae5ae9f812426c5d5db7476a304b110736ccb3
100644
--- a/Source/core/html/HTMLCanvasElement.cpp
+++ b/Source/core/html/HTMLCanvasElement.cpp
@@ -39,6 +39,7 @@
 #include "core/page/Frame.h"
 #include "RuntimeEnabledFeatures.h"
 #include "core/page/Settings.h"
+#include "core/platform/HistogramSupport.h"
 #include "core/platform/MIMETypeRegistry.h"
 #include "core/platform/graphics/GraphicsContextStateSaver.h"
 #include "core/platform/graphics/ImageBuffer.h"
@@ -152,6 +153,14 @@ CanvasRenderingContext* HTMLCanvasElement::getContext(const
String& type, Canvas
     // context is already 2D, just return that. If the existing context is
WebGL, then destroy it
     // before creating a new 2D context. Vice versa when requesting a WebGL
canvas. Requesting a
     // context with any other type string will destroy any existing context.
+    enum ContextType {
+        Context2d,
+        ContextWebkit3d,
+        ContextExperimentalWebgl,
+        ContextWebgl,
+        // Only add new items to the end and keep the order of existing items.
+        ContextTypeCount,
+    };
 
     // FIXME - The code depends on the context not going away once created, to
prevent JS from
     // seeing a dangling pointer. So for now we will disallow the context from
being changed
@@ -160,6 +169,7 @@ CanvasRenderingContext* HTMLCanvasElement::getContext(const
String& type, Canvas
         if (m_context && !m_context->is2d())
             return 0;
         if (!m_context) {
+            HistogramSupport::histogramEnumeration("Canvas.ContextType",
Context2d, ContextTypeCount);
             m_context = CanvasRenderingContext2D::create(this,
RuntimeEnabledFeatures::experimentalCanvasFeaturesEnabled() ?
static_cast<Canvas2DContextAttributes*>(attrs) : 0, document()->inQuirksMode());
             if (m_context)
                 scheduleLayerUpdate();
@@ -169,17 +179,24 @@ CanvasRenderingContext*
HTMLCanvasElement::getContext(const String& type, Canvas
 
     Settings* settings = document()->settings();
     if (settings && settings->webGLEnabled()) {
-
         // Accept the legacy "webkit-3d" name as well as the provisional
"experimental-webgl" name.
-        bool is3dContext = (type == "webkit-3d") || (type ==
"experimental-webgl");
-
         // Now that WebGL is ratified, we will also accept "webgl" as the
context name in Chrome.
-        is3dContext |= (type == "webgl");
+        ContextType contextType;
+        bool is3dContext = true;
+        if (type == "webkit-3d")
+            contextType = ContextWebkit3d;
+        else if (type == "experimental-webgl")
+            contextType = ContextExperimentalWebgl;
+        else if (type == "webgl")
+            contextType = ContextWebgl;
+        else
+            is3dContext = false;
 
         if (is3dContext) {
             if (m_context && !m_context->is3d())
                 return 0;
             if (!m_context) {
+                HistogramSupport::histogramEnumeration("Canvas.ContextType",
contextType, ContextTypeCount);
                 m_context = WebGLRenderingContext::create(this,
static_cast<WebGLContextAttributes*>(attrs));
                 if (m_context)
                     scheduleLayerUpdate();

[commit-bot: I haz the power, 2013-08-06 13:56:23]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/skyostil@chromium.org/21861002/5001

[commit-bot: I haz the power, 2013-08-06 17:30:53]

Change committed as 155620